Health Consultation

REVIEW OF GROUNDWATER DATA (2005 EPA DELINEATION INVESTIGATION)

SIGMONrsquoS SEPTIC TANK SERVICE SITE

STATESVILLE IREDELL COUNTY NORTH CAROLINA

REGION IV

EPA FACILITY ID NCD062555792

OCTOBER 12 2006

US DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service

Agency for Toxic Substances and Disease Registry Division of Health Assessment and Consultation

Atlanta Georgia 30333

Health Consultation A Note of Explanation

An ATSDR health consultation is a verbal or written response from ATSDR to a specific request for information about health risks related to a specific site a chemical release or the presence of hazardous material In order to prevent or mitigate exposures a consultation may lead to specific actions such as restricting use of or replacing water supplies intensifying environmental sampling restricting site access or removing the contaminated material

In addition consultations may recommend additional public health actions such as conducting health surveillance activities to evaluate exposure or trends in adverse health outcomes conducting biological indicators of exposure studies to assess exposure and providing health education for health care providers and community members This concludes the health consultation process for this site unless additional information is obtained by ATSDR which in the Agencyrsquos opinion indicates a need to revise or append the conclusions previously issued

You May Contact ATSDR Toll Free at 1-800-CDC-INFO

or Visit our Home Page at httpwwwatsdrcdcgov

Health Consultation A Note of Explanation

An ATSDR health consultation is a verbal or written response from ATSDR to a specific request for information about health risks related to a specific site a chemical release or the presence of hazardous material In order to prevent or mitigate exposures a consultation may lead to specific actions such as restricting use of or replacing water supplies intensifying environmental sampling restricting site access or removing the contaminated material

In addition consultations may recommend additional public health actions such as conducting health surveillance activities to evaluate exposure or trends in adverse health outcomes conducting biological indicators of exposure studies to assess exposure and providing health education for health care providers and community members This concludes the health consultation process for this site unless additional information is obtained by ATSDR which in the Agencyrsquos opinion indicates a need to revise or append the conclusions previously issued

You May Contact ATSDR Toll Free at 1-800-CDC-INFO

or Visit our Home Page at httpwwwatsdrcdcgov

HEALTH CONSULTATION

REVIEW OF GROUNDWATER DATA (2005 EPA DELINEATION INVESTIGATION)

SIGMONrsquoS SEPTIC TANK SERVICE SITE

STATESVILLE IREDELL COUNTY NORTH CAROLINA

REGION IV

EPA FACILITY ID NCD062555792

Prepared By

US Department of Health and Human Services Agency for Toxic Substances and Disease Registry Division of Health Assessment and Consultation

Table of Contents Background and Statement of Issues 1

Exposure Pathways 5

Appendix A Comparison Values A-1

Figure 3 Monitoring and potable well locations Sigmonrsquos Septic Tank site Statesville North

Discussion 3 Environmental Sampling and Chemical Analyses3

Rationale for the Selective Screening of Substances in Groundwater3

Other Public Health Concerns 6 Public Health Implications6

Child Health Considerations 11 Conclusions 12 Recommendations12 Public Health Action Plan13 Authors 14 References 16

Appendix B TablesB-1 Table 1 Chemical Levels Considered a No Apparent Health Hazard B-2 Table 2 Chemical Levels Considered a Nonapparent Health HazardB-4 Table Notes Footnotes for Tables 3 Through 11 B-6 Table 3 Detected Substances Found in Private Well PW-01B-7 Table 4 Detected Substances Found in Private Well PW-03B-8 Table 5 Detected Substances Found in Private Well PW-04B-10 Table 6 Detected Substances Found in Private Well PW-05B-11 Table 7 Detected Substances Found in Private Well PW-06B-12 Table 7 Detected Substances Found in Private Well PW-06B-13 Table 9Detected Substances Found in Private Well PW-07B-14 Table 10 Detected Substances Found in Private Well PW-08B-15 Table 11 Detected Substances Found in Private Well PW-09B-16 Table 12 Detected Substances Found in Private Well PW-10B-17 Table 13 Detected Substances Found in Private Well PW-11B-18 Table 14 Detected Substances Found in Private Well PW-12B-19 Table 15 Detected Substances Found in Private Wells Near the Sigmon Facility B-20

Appendix C FiguresC-1 Figure 1 Site layout map Sigmonrsquos Septic Tank Site Statesville North Carolina C-2 Figure 2 Sigmonrsquos Septic Tank Site Statesville North Carolina C-3

Carolina C-4 Figure 4 Groundwater potentiometric surface map May 21 2004 Sigmonrsquos Septic Tank site Statesville North CarolinaC-5

Background and Statement of Issues On June 23 2005 the Agency for Toxic Substances and Disease Registry (ATSDR) received additional sampling and analysis data of the groundwater medium at the Sigmon Septic Tank Service Site a hazardous waste site under investigation by the U S Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia (John A Blanchard Black amp Veatch Special Projects Corporation EPA Contractor e-mail of June 2005 copied David S Sutton Division of Health Assessment and Consultation ATSDR) The additional data were collected as part of a delineation investigation conducted at the site during the week of April 18 2005 The investigation was a follow-up action by EPA to its initial delineation investigation (October 2002ndashApril 2004) of the site to reassess lead and nitrate levels in nearby private wells None of the wells showed lead concentrations at levels of health concern during the 2005 investigation Moreover EPA has placed the Sigmon Septic Tank Site on its Nationalrsquos Priority List (NPL) thus the need for cleaning up the site is a priority (70 FR 21644 April 27 2005) Hazardous waste sites placed on the NPL must follow the procedural guidelines for cleanup as described and documented under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA)

ATSDR reviewed the additional data and assessed whether exposures to substances detected in the groundwater pose any potential impacts to the health of nearby private well users The review served as a follow-up to an earlier request from ATSDRrsquos Division of Regional Operations (DRO) Region IV Office Atlanta Georgia DRO requested ATSDR to determine the potential public health impacts that the Sigmon Septic Tank Service Sitemdasha former septic tank service and waste removal businessmdashwould have on nearby private well users (Benjamin Moore Division of Regional Operations ATSDR Region 4 e-mail of October 2004 to Susan Moore Division of Health Assessment and Consultation ATSDR) The request actually originated from the United States Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia EPA initially sent analytical results of groundwater samples to ATSDRs DRO Region IV Office for public health review and evaluation (Warren Dixon EPA Region 4 e-mail of October 2004 to Benjamin Moore ATSDR Division of Regional Operations) These earlier groundwater samples were also collected from the site as a part of the delineation investigations conducted in October 2002 and April 2004 ATSDR completed its assessment for the earlier request and released its findings in a public health consultation (PHC) (ATSDR 2006)

Sigmon Septic Tank Service Site (CERCLIS No NCD062555792) is located at 1268 Eufola Road approximately 5 miles southwest of Statesville Iredell County North Carolina (NCDENR 1998 2000 Black amp Veatch 2004) This site has been listed under several names including Sigmons Septic Tank Service AAA Enterprises and Sigmon Environmental Services Services provided by the business have included the pumping and removal of septic tank wastes and heavy sludges for residential commercial and industrial customers installation and repair of septic tanks and other waste removal services to various industries

Both federal and state environmental regulatory agencies have for several years investigated the groundwater pathway at the site (NCDENR 1998 2000 Black amp Veatch 2004) The earliest that the site groundwater was sampled began in 1987 at which time water samples were collected

1

from on-site monitoring wells Starting in 1991 water samples were collected from nearby private wells

ATSDR released a PHC for the site on March 29 2002 assessing the sitersquos groundwater pathway ATSDR determined that the groundwater pathway appeared to be of concern because two private wells showed nitrate levels greater than 10000 parts per billion (ppb) (ATSDR 2002a) Infants (0ndash6 months) who consume formula prepared with water containing nitrate levels greater than 10000 ppb have an increased risk of higher methemoglobin levels (EPA 1990 Bosch et al 1950 Walton 1951) Similarly fetuses might be exposed to potential health risks if pregnant females drink water with comparable nitrate levels (Muhrer et al 1959 MMWR 1996) ATSDR released another PHC on April 3 2006 that assessed the sites groundwater pathway based on EPArsquos initial delineation investigation of the site (October 2002ndashApril 2004) ATSDR determined that the groundwater pathway again appeared to be of concern because two private wells showed maximum lead levels of 50 and 140 ppb Although no notable cause surfaced as to why the groundwater samples contained these high lead levels some notable causes can be attributed to either lead plumbing or improper sampling protocol Whatever the real cause the maximum detected levels in the private wells presented the potential of adversely affecting public health The table below summarizes ATSDRrsquos assessment of the sitersquos groundwater pathway thus far

Groundwater Public Health Consultation Sampling Data Release Date

1991 ndash 1999 March 29 2002

October 2002 ndash April 2004 April 3 2006

April 2005 this report

Figure 1 shows the Sigmon Septic Tank Service Site and nearby residences Former waste areas still remain at the site These were used for waste handling and disposal during past operations at the septic tank service facility These areas include the Lagoon Area Waste Pile and Open Pits (Figure 1) These former waste areas are believed to be the chief source of groundwater problems within the area In its previous PHC ATSDR recommended that environmental regulatory agencies consider removing these areas from the Sigmon Septic Tank Service Site (ATSDR 2002a) EPA is presently considering this recommendation while its site investigations continue ATSDR believes that removing the remaining waste areas at the site could reduce or even eliminate potential releases of hazardous substances to the surrounding soil groundwater or surface water thereby reducing or eliminating any potential impacts on public health

2

Discussion Environmental Sampling and Chemical Analyses ATSDR reviewed groundwater samples collected in April 2005 from 11 private wells The water samples were collected as a follow-up response to determine whether the private wells contained any significant levels of lead and nitrates The private well owners use the groundwater for drinking and other domestic purposes (eg washing bathing irrigation)

Rationale for the Selective Screening of Substances in Groundwater The first step in any public health evaluation or assessment process is the application of conservative screening values to the available sampling data This phase of the process helps to rule out any site-specific substances that would not pose a public health hazard under virtually any plausible exposure scenario The substances remaining after the preliminary screen would then require further analysis to evaluate their potential for causing adverse health effects under site-specific exposure conditions (ATSDR 2005) It is during this second phase of the process that potential public health hazards are identified The preliminary screening phase does not identify toxic exposures it merely eliminates obviously nontoxic exposures so that the evaluation of public health implications can focus on a reduced list of substances

A substance is initially selected for further public health evaluation if its maximum detected level in groundwater exceeds its most relevant water comparison value (CV) A substance is also initially selected for further evaluation if it is detected in groundwater and no water CV exists for the substance Following this initial screening the detected concentration(s) of the selected substance(s) are compared to concentration ranges considered to pose no apparent public health hazards in the two previous PHCs released for the site (ATSDR 2002a 2006) see Tables 1 and 2 To avoid repeating work already done if the detected concentrations fell within the concentration ranges previously considered to pose a no apparent public health hazard the substances were not reevaluated

2005 Delineation Investigation EPA contracted Black and Veatch Special Projects Corporation (Black amp Veatch) to conduct follow-up sampling activities at the Sigmon Septic Tank Service Site in accordance with its Environmental Investigations Standard Operating Procedures and Quality Assurance Manual (EPA 1997) In April 2005 samples were taken from the groundwater

Twelve groundwater samples were collected from 11 private wells (Figures 2 and 3) and were subsequently analyzed for metals volatile organic compounds (VOCs) semi-volatile organic compounds (SVOCs) pesticidespolychlorinated biphenyls (PCBs) and nitrates Tables 3 through 14 (Appendix B) list the results of these analyses The results were compared to water comparison values (CVs) together with the selection screening criteria to determine whether further analysis was indicated for any of these substances The following is a summary of ATSDRrsquos initial public health screen for each private well

Private well PW-01 Of the 10 substances detected in the well none exceeded any available water CV nevertheless 3 substances were found for which CVs were not available The concentrations of these 3 substances were within ranges of levels

3

x

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Table of Contents Background and Statement of Issues 1

Exposure Pathways 5

Appendix A Comparison Values A-1

Figure 3 Monitoring and potable well locations Sigmonrsquos Septic Tank site Statesville North

Discussion 3 Environmental Sampling and Chemical Analyses3

Rationale for the Selective Screening of Substances in Groundwater3

Other Public Health Concerns 6 Public Health Implications6

Child Health Considerations 11 Conclusions 12 Recommendations12 Public Health Action Plan13 Authors 14 References 16

Appendix B TablesB-1 Table 1 Chemical Levels Considered a No Apparent Health Hazard B-2 Table 2 Chemical Levels Considered a Nonapparent Health HazardB-4 Table Notes Footnotes for Tables 3 Through 11 B-6 Table 3 Detected Substances Found in Private Well PW-01B-7 Table 4 Detected Substances Found in Private Well PW-03B-8 Table 5 Detected Substances Found in Private Well PW-04B-10 Table 6 Detected Substances Found in Private Well PW-05B-11 Table 7 Detected Substances Found in Private Well PW-06B-12 Table 7 Detected Substances Found in Private Well PW-06B-13 Table 9Detected Substances Found in Private Well PW-07B-14 Table 10 Detected Substances Found in Private Well PW-08B-15 Table 11 Detected Substances Found in Private Well PW-09B-16 Table 12 Detected Substances Found in Private Well PW-10B-17 Table 13 Detected Substances Found in Private Well PW-11B-18 Table 14 Detected Substances Found in Private Well PW-12B-19 Table 15 Detected Substances Found in Private Wells Near the Sigmon Facility B-20

Appendix C FiguresC-1 Figure 1 Site layout map Sigmonrsquos Septic Tank Site Statesville North Carolina C-2 Figure 2 Sigmonrsquos Septic Tank Site Statesville North Carolina C-3

Carolina C-4 Figure 4 Groundwater potentiometric surface map May 21 2004 Sigmonrsquos Septic Tank site Statesville North CarolinaC-5

Background and Statement of Issues On June 23 2005 the Agency for Toxic Substances and Disease Registry (ATSDR) received additional sampling and analysis data of the groundwater medium at the Sigmon Septic Tank Service Site a hazardous waste site under investigation by the U S Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia (John A Blanchard Black amp Veatch Special Projects Corporation EPA Contractor e-mail of June 2005 copied David S Sutton Division of Health Assessment and Consultation ATSDR) The additional data were collected as part of a delineation investigation conducted at the site during the week of April 18 2005 The investigation was a follow-up action by EPA to its initial delineation investigation (October 2002ndashApril 2004) of the site to reassess lead and nitrate levels in nearby private wells None of the wells showed lead concentrations at levels of health concern during the 2005 investigation Moreover EPA has placed the Sigmon Septic Tank Site on its Nationalrsquos Priority List (NPL) thus the need for cleaning up the site is a priority (70 FR 21644 April 27 2005) Hazardous waste sites placed on the NPL must follow the procedural guidelines for cleanup as described and documented under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA)

ATSDR reviewed the additional data and assessed whether exposures to substances detected in the groundwater pose any potential impacts to the health of nearby private well users The review served as a follow-up to an earlier request from ATSDRrsquos Division of Regional Operations (DRO) Region IV Office Atlanta Georgia DRO requested ATSDR to determine the potential public health impacts that the Sigmon Septic Tank Service Sitemdasha former septic tank service and waste removal businessmdashwould have on nearby private well users (Benjamin Moore Division of Regional Operations ATSDR Region 4 e-mail of October 2004 to Susan Moore Division of Health Assessment and Consultation ATSDR) The request actually originated from the United States Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia EPA initially sent analytical results of groundwater samples to ATSDRs DRO Region IV Office for public health review and evaluation (Warren Dixon EPA Region 4 e-mail of October 2004 to Benjamin Moore ATSDR Division of Regional Operations) These earlier groundwater samples were also collected from the site as a part of the delineation investigations conducted in October 2002 and April 2004 ATSDR completed its assessment for the earlier request and released its findings in a public health consultation (PHC) (ATSDR 2006)

Sigmon Septic Tank Service Site (CERCLIS No NCD062555792) is located at 1268 Eufola Road approximately 5 miles southwest of Statesville Iredell County North Carolina (NCDENR 1998 2000 Black amp Veatch 2004) This site has been listed under several names including Sigmons Septic Tank Service AAA Enterprises and Sigmon Environmental Services Services provided by the business have included the pumping and removal of septic tank wastes and heavy sludges for residential commercial and industrial customers installation and repair of septic tanks and other waste removal services to various industries

Both federal and state environmental regulatory agencies have for several years investigated the groundwater pathway at the site (NCDENR 1998 2000 Black amp Veatch 2004) The earliest that the site groundwater was sampled began in 1987 at which time water samples were collected

1

from on-site monitoring wells Starting in 1991 water samples were collected from nearby private wells

ATSDR released a PHC for the site on March 29 2002 assessing the sitersquos groundwater pathway ATSDR determined that the groundwater pathway appeared to be of concern because two private wells showed nitrate levels greater than 10000 parts per billion (ppb) (ATSDR 2002a) Infants (0ndash6 months) who consume formula prepared with water containing nitrate levels greater than 10000 ppb have an increased risk of higher methemoglobin levels (EPA 1990 Bosch et al 1950 Walton 1951) Similarly fetuses might be exposed to potential health risks if pregnant females drink water with comparable nitrate levels (Muhrer et al 1959 MMWR 1996) ATSDR released another PHC on April 3 2006 that assessed the sites groundwater pathway based on EPArsquos initial delineation investigation of the site (October 2002ndashApril 2004) ATSDR determined that the groundwater pathway again appeared to be of concern because two private wells showed maximum lead levels of 50 and 140 ppb Although no notable cause surfaced as to why the groundwater samples contained these high lead levels some notable causes can be attributed to either lead plumbing or improper sampling protocol Whatever the real cause the maximum detected levels in the private wells presented the potential of adversely affecting public health The table below summarizes ATSDRrsquos assessment of the sitersquos groundwater pathway thus far

Groundwater Public Health Consultation Sampling Data Release Date

1991 ndash 1999 March 29 2002

October 2002 ndash April 2004 April 3 2006

April 2005 this report

Figure 1 shows the Sigmon Septic Tank Service Site and nearby residences Former waste areas still remain at the site These were used for waste handling and disposal during past operations at the septic tank service facility These areas include the Lagoon Area Waste Pile and Open Pits (Figure 1) These former waste areas are believed to be the chief source of groundwater problems within the area In its previous PHC ATSDR recommended that environmental regulatory agencies consider removing these areas from the Sigmon Septic Tank Service Site (ATSDR 2002a) EPA is presently considering this recommendation while its site investigations continue ATSDR believes that removing the remaining waste areas at the site could reduce or even eliminate potential releases of hazardous substances to the surrounding soil groundwater or surface water thereby reducing or eliminating any potential impacts on public health

2

Discussion Environmental Sampling and Chemical Analyses ATSDR reviewed groundwater samples collected in April 2005 from 11 private wells The water samples were collected as a follow-up response to determine whether the private wells contained any significant levels of lead and nitrates The private well owners use the groundwater for drinking and other domestic purposes (eg washing bathing irrigation)

Rationale for the Selective Screening of Substances in Groundwater The first step in any public health evaluation or assessment process is the application of conservative screening values to the available sampling data This phase of the process helps to rule out any site-specific substances that would not pose a public health hazard under virtually any plausible exposure scenario The substances remaining after the preliminary screen would then require further analysis to evaluate their potential for causing adverse health effects under site-specific exposure conditions (ATSDR 2005) It is during this second phase of the process that potential public health hazards are identified The preliminary screening phase does not identify toxic exposures it merely eliminates obviously nontoxic exposures so that the evaluation of public health implications can focus on a reduced list of substances

A substance is initially selected for further public health evaluation if its maximum detected level in groundwater exceeds its most relevant water comparison value (CV) A substance is also initially selected for further evaluation if it is detected in groundwater and no water CV exists for the substance Following this initial screening the detected concentration(s) of the selected substance(s) are compared to concentration ranges considered to pose no apparent public health hazards in the two previous PHCs released for the site (ATSDR 2002a 2006) see Tables 1 and 2 To avoid repeating work already done if the detected concentrations fell within the concentration ranges previously considered to pose a no apparent public health hazard the substances were not reevaluated

2005 Delineation Investigation EPA contracted Black and Veatch Special Projects Corporation (Black amp Veatch) to conduct follow-up sampling activities at the Sigmon Septic Tank Service Site in accordance with its Environmental Investigations Standard Operating Procedures and Quality Assurance Manual (EPA 1997) In April 2005 samples were taken from the groundwater

Twelve groundwater samples were collected from 11 private wells (Figures 2 and 3) and were subsequently analyzed for metals volatile organic compounds (VOCs) semi-volatile organic compounds (SVOCs) pesticidespolychlorinated biphenyls (PCBs) and nitrates Tables 3 through 14 (Appendix B) list the results of these analyses The results were compared to water comparison values (CVs) together with the selection screening criteria to determine whether further analysis was indicated for any of these substances The following is a summary of ATSDRrsquos initial public health screen for each private well

Private well PW-01 Of the 10 substances detected in the well none exceeded any available water CV nevertheless 3 substances were found for which CVs were not available The concentrations of these 3 substances were within ranges of levels

3

x

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Background and Statement of Issues On June 23 2005 the Agency for Toxic Substances and Disease Registry (ATSDR) received additional sampling and analysis data of the groundwater medium at the Sigmon Septic Tank Service Site a hazardous waste site under investigation by the U S Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia (John A Blanchard Black amp Veatch Special Projects Corporation EPA Contractor e-mail of June 2005 copied David S Sutton Division of Health Assessment and Consultation ATSDR) The additional data were collected as part of a delineation investigation conducted at the site during the week of April 18 2005 The investigation was a follow-up action by EPA to its initial delineation investigation (October 2002ndashApril 2004) of the site to reassess lead and nitrate levels in nearby private wells None of the wells showed lead concentrations at levels of health concern during the 2005 investigation Moreover EPA has placed the Sigmon Septic Tank Site on its Nationalrsquos Priority List (NPL) thus the need for cleaning up the site is a priority (70 FR 21644 April 27 2005) Hazardous waste sites placed on the NPL must follow the procedural guidelines for cleanup as described and documented under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA)

ATSDR reviewed the additional data and assessed whether exposures to substances detected in the groundwater pose any potential impacts to the health of nearby private well users The review served as a follow-up to an earlier request from ATSDRrsquos Division of Regional Operations (DRO) Region IV Office Atlanta Georgia DRO requested ATSDR to determine the potential public health impacts that the Sigmon Septic Tank Service Sitemdasha former septic tank service and waste removal businessmdashwould have on nearby private well users (Benjamin Moore Division of Regional Operations ATSDR Region 4 e-mail of October 2004 to Susan Moore Division of Health Assessment and Consultation ATSDR) The request actually originated from the United States Environmental Protection Agency (EPA) Region IV Office Atlanta Georgia EPA initially sent analytical results of groundwater samples to ATSDRs DRO Region IV Office for public health review and evaluation (Warren Dixon EPA Region 4 e-mail of October 2004 to Benjamin Moore ATSDR Division of Regional Operations) These earlier groundwater samples were also collected from the site as a part of the delineation investigations conducted in October 2002 and April 2004 ATSDR completed its assessment for the earlier request and released its findings in a public health consultation (PHC) (ATSDR 2006)

Sigmon Septic Tank Service Site (CERCLIS No NCD062555792) is located at 1268 Eufola Road approximately 5 miles southwest of Statesville Iredell County North Carolina (NCDENR 1998 2000 Black amp Veatch 2004) This site has been listed under several names including Sigmons Septic Tank Service AAA Enterprises and Sigmon Environmental Services Services provided by the business have included the pumping and removal of septic tank wastes and heavy sludges for residential commercial and industrial customers installation and repair of septic tanks and other waste removal services to various industries

Both federal and state environmental regulatory agencies have for several years investigated the groundwater pathway at the site (NCDENR 1998 2000 Black amp Veatch 2004) The earliest that the site groundwater was sampled began in 1987 at which time water samples were collected

1

from on-site monitoring wells Starting in 1991 water samples were collected from nearby private wells

ATSDR released a PHC for the site on March 29 2002 assessing the sitersquos groundwater pathway ATSDR determined that the groundwater pathway appeared to be of concern because two private wells showed nitrate levels greater than 10000 parts per billion (ppb) (ATSDR 2002a) Infants (0ndash6 months) who consume formula prepared with water containing nitrate levels greater than 10000 ppb have an increased risk of higher methemoglobin levels (EPA 1990 Bosch et al 1950 Walton 1951) Similarly fetuses might be exposed to potential health risks if pregnant females drink water with comparable nitrate levels (Muhrer et al 1959 MMWR 1996) ATSDR released another PHC on April 3 2006 that assessed the sites groundwater pathway based on EPArsquos initial delineation investigation of the site (October 2002ndashApril 2004) ATSDR determined that the groundwater pathway again appeared to be of concern because two private wells showed maximum lead levels of 50 and 140 ppb Although no notable cause surfaced as to why the groundwater samples contained these high lead levels some notable causes can be attributed to either lead plumbing or improper sampling protocol Whatever the real cause the maximum detected levels in the private wells presented the potential of adversely affecting public health The table below summarizes ATSDRrsquos assessment of the sitersquos groundwater pathway thus far

Groundwater Public Health Consultation Sampling Data Release Date

1991 ndash 1999 March 29 2002

October 2002 ndash April 2004 April 3 2006

April 2005 this report

Figure 1 shows the Sigmon Septic Tank Service Site and nearby residences Former waste areas still remain at the site These were used for waste handling and disposal during past operations at the septic tank service facility These areas include the Lagoon Area Waste Pile and Open Pits (Figure 1) These former waste areas are believed to be the chief source of groundwater problems within the area In its previous PHC ATSDR recommended that environmental regulatory agencies consider removing these areas from the Sigmon Septic Tank Service Site (ATSDR 2002a) EPA is presently considering this recommendation while its site investigations continue ATSDR believes that removing the remaining waste areas at the site could reduce or even eliminate potential releases of hazardous substances to the surrounding soil groundwater or surface water thereby reducing or eliminating any potential impacts on public health

2

Discussion Environmental Sampling and Chemical Analyses ATSDR reviewed groundwater samples collected in April 2005 from 11 private wells The water samples were collected as a follow-up response to determine whether the private wells contained any significant levels of lead and nitrates The private well owners use the groundwater for drinking and other domestic purposes (eg washing bathing irrigation)

Rationale for the Selective Screening of Substances in Groundwater The first step in any public health evaluation or assessment process is the application of conservative screening values to the available sampling data This phase of the process helps to rule out any site-specific substances that would not pose a public health hazard under virtually any plausible exposure scenario The substances remaining after the preliminary screen would then require further analysis to evaluate their potential for causing adverse health effects under site-specific exposure conditions (ATSDR 2005) It is during this second phase of the process that potential public health hazards are identified The preliminary screening phase does not identify toxic exposures it merely eliminates obviously nontoxic exposures so that the evaluation of public health implications can focus on a reduced list of substances

A substance is initially selected for further public health evaluation if its maximum detected level in groundwater exceeds its most relevant water comparison value (CV) A substance is also initially selected for further evaluation if it is detected in groundwater and no water CV exists for the substance Following this initial screening the detected concentration(s) of the selected substance(s) are compared to concentration ranges considered to pose no apparent public health hazards in the two previous PHCs released for the site (ATSDR 2002a 2006) see Tables 1 and 2 To avoid repeating work already done if the detected concentrations fell within the concentration ranges previously considered to pose a no apparent public health hazard the substances were not reevaluated

2005 Delineation Investigation EPA contracted Black and Veatch Special Projects Corporation (Black amp Veatch) to conduct follow-up sampling activities at the Sigmon Septic Tank Service Site in accordance with its Environmental Investigations Standard Operating Procedures and Quality Assurance Manual (EPA 1997) In April 2005 samples were taken from the groundwater

Twelve groundwater samples were collected from 11 private wells (Figures 2 and 3) and were subsequently analyzed for metals volatile organic compounds (VOCs) semi-volatile organic compounds (SVOCs) pesticidespolychlorinated biphenyls (PCBs) and nitrates Tables 3 through 14 (Appendix B) list the results of these analyses The results were compared to water comparison values (CVs) together with the selection screening criteria to determine whether further analysis was indicated for any of these substances The following is a summary of ATSDRrsquos initial public health screen for each private well

Private well PW-01 Of the 10 substances detected in the well none exceeded any available water CV nevertheless 3 substances were found for which CVs were not available The concentrations of these 3 substances were within ranges of levels

3

x

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

from on-site monitoring wells Starting in 1991 water samples were collected from nearby private wells

ATSDR released a PHC for the site on March 29 2002 assessing the sitersquos groundwater pathway ATSDR determined that the groundwater pathway appeared to be of concern because two private wells showed nitrate levels greater than 10000 parts per billion (ppb) (ATSDR 2002a) Infants (0ndash6 months) who consume formula prepared with water containing nitrate levels greater than 10000 ppb have an increased risk of higher methemoglobin levels (EPA 1990 Bosch et al 1950 Walton 1951) Similarly fetuses might be exposed to potential health risks if pregnant females drink water with comparable nitrate levels (Muhrer et al 1959 MMWR 1996) ATSDR released another PHC on April 3 2006 that assessed the sites groundwater pathway based on EPArsquos initial delineation investigation of the site (October 2002ndashApril 2004) ATSDR determined that the groundwater pathway again appeared to be of concern because two private wells showed maximum lead levels of 50 and 140 ppb Although no notable cause surfaced as to why the groundwater samples contained these high lead levels some notable causes can be attributed to either lead plumbing or improper sampling protocol Whatever the real cause the maximum detected levels in the private wells presented the potential of adversely affecting public health The table below summarizes ATSDRrsquos assessment of the sitersquos groundwater pathway thus far

Groundwater Public Health Consultation Sampling Data Release Date

1991 ndash 1999 March 29 2002

October 2002 ndash April 2004 April 3 2006

April 2005 this report

Figure 1 shows the Sigmon Septic Tank Service Site and nearby residences Former waste areas still remain at the site These were used for waste handling and disposal during past operations at the septic tank service facility These areas include the Lagoon Area Waste Pile and Open Pits (Figure 1) These former waste areas are believed to be the chief source of groundwater problems within the area In its previous PHC ATSDR recommended that environmental regulatory agencies consider removing these areas from the Sigmon Septic Tank Service Site (ATSDR 2002a) EPA is presently considering this recommendation while its site investigations continue ATSDR believes that removing the remaining waste areas at the site could reduce or even eliminate potential releases of hazardous substances to the surrounding soil groundwater or surface water thereby reducing or eliminating any potential impacts on public health

2

Discussion Environmental Sampling and Chemical Analyses ATSDR reviewed groundwater samples collected in April 2005 from 11 private wells The water samples were collected as a follow-up response to determine whether the private wells contained any significant levels of lead and nitrates The private well owners use the groundwater for drinking and other domestic purposes (eg washing bathing irrigation)

Rationale for the Selective Screening of Substances in Groundwater The first step in any public health evaluation or assessment process is the application of conservative screening values to the available sampling data This phase of the process helps to rule out any site-specific substances that would not pose a public health hazard under virtually any plausible exposure scenario The substances remaining after the preliminary screen would then require further analysis to evaluate their potential for causing adverse health effects under site-specific exposure conditions (ATSDR 2005) It is during this second phase of the process that potential public health hazards are identified The preliminary screening phase does not identify toxic exposures it merely eliminates obviously nontoxic exposures so that the evaluation of public health implications can focus on a reduced list of substances

A substance is initially selected for further public health evaluation if its maximum detected level in groundwater exceeds its most relevant water comparison value (CV) A substance is also initially selected for further evaluation if it is detected in groundwater and no water CV exists for the substance Following this initial screening the detected concentration(s) of the selected substance(s) are compared to concentration ranges considered to pose no apparent public health hazards in the two previous PHCs released for the site (ATSDR 2002a 2006) see Tables 1 and 2 To avoid repeating work already done if the detected concentrations fell within the concentration ranges previously considered to pose a no apparent public health hazard the substances were not reevaluated

2005 Delineation Investigation EPA contracted Black and Veatch Special Projects Corporation (Black amp Veatch) to conduct follow-up sampling activities at the Sigmon Septic Tank Service Site in accordance with its Environmental Investigations Standard Operating Procedures and Quality Assurance Manual (EPA 1997) In April 2005 samples were taken from the groundwater

Twelve groundwater samples were collected from 11 private wells (Figures 2 and 3) and were subsequently analyzed for metals volatile organic compounds (VOCs) semi-volatile organic compounds (SVOCs) pesticidespolychlorinated biphenyls (PCBs) and nitrates Tables 3 through 14 (Appendix B) list the results of these analyses The results were compared to water comparison values (CVs) together with the selection screening criteria to determine whether further analysis was indicated for any of these substances The following is a summary of ATSDRrsquos initial public health screen for each private well

Private well PW-01 Of the 10 substances detected in the well none exceeded any available water CV nevertheless 3 substances were found for which CVs were not available The concentrations of these 3 substances were within ranges of levels

3

x

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Discussion Environmental Sampling and Chemical Analyses ATSDR reviewed groundwater samples collected in April 2005 from 11 private wells The water samples were collected as a follow-up response to determine whether the private wells contained any significant levels of lead and nitrates The private well owners use the groundwater for drinking and other domestic purposes (eg washing bathing irrigation)

Rationale for the Selective Screening of Substances in Groundwater The first step in any public health evaluation or assessment process is the application of conservative screening values to the available sampling data This phase of the process helps to rule out any site-specific substances that would not pose a public health hazard under virtually any plausible exposure scenario The substances remaining after the preliminary screen would then require further analysis to evaluate their potential for causing adverse health effects under site-specific exposure conditions (ATSDR 2005) It is during this second phase of the process that potential public health hazards are identified The preliminary screening phase does not identify toxic exposures it merely eliminates obviously nontoxic exposures so that the evaluation of public health implications can focus on a reduced list of substances

A substance is initially selected for further public health evaluation if its maximum detected level in groundwater exceeds its most relevant water comparison value (CV) A substance is also initially selected for further evaluation if it is detected in groundwater and no water CV exists for the substance Following this initial screening the detected concentration(s) of the selected substance(s) are compared to concentration ranges considered to pose no apparent public health hazards in the two previous PHCs released for the site (ATSDR 2002a 2006) see Tables 1 and 2 To avoid repeating work already done if the detected concentrations fell within the concentration ranges previously considered to pose a no apparent public health hazard the substances were not reevaluated

2005 Delineation Investigation EPA contracted Black and Veatch Special Projects Corporation (Black amp Veatch) to conduct follow-up sampling activities at the Sigmon Septic Tank Service Site in accordance with its Environmental Investigations Standard Operating Procedures and Quality Assurance Manual (EPA 1997) In April 2005 samples were taken from the groundwater

Twelve groundwater samples were collected from 11 private wells (Figures 2 and 3) and were subsequently analyzed for metals volatile organic compounds (VOCs) semi-volatile organic compounds (SVOCs) pesticidespolychlorinated biphenyls (PCBs) and nitrates Tables 3 through 14 (Appendix B) list the results of these analyses The results were compared to water comparison values (CVs) together with the selection screening criteria to determine whether further analysis was indicated for any of these substances The following is a summary of ATSDRrsquos initial public health screen for each private well

Private well PW-01 Of the 10 substances detected in the well none exceeded any available water CV nevertheless 3 substances were found for which CVs were not available The concentrations of these 3 substances were within ranges of levels

3

x

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

previously considered to pose no apparent public health hazard at this site (ATSDR 2002a 2006) Accordingly none of the substances in PW-01 were selected for further public health evaluation (Table 3)

x Private well PW-03 Of the 26 substances detected in the well 4 showed maximum levels that exceeded available water CVs however 2 of these substances did not require further public health evaluation because their maximum measured concentrations were within ranges considered to pose a no apparent public health hazard Three other substances were also detected in the well that had no available water CVs however all 3 were within ranges considered to pose a no apparent public health hazard Thus two of the substances detected in PW-03 were selected for further public health evaluation (Table 4) One was nitrates a previous concern in ATSDRrsquos March 2002 assessment of the sitersquos groundwater pathway (ATSDR 2002a) and the other was vinyl chloride

x Private well PW-04 Of the 14 substances detected in this well none exceeded any available water CV That said 3 of these substances had no available water CV and all 3 were within ranges considered a no apparent public health hazard Therefore none of the substances detected in PW-04 were selected for further evaluation (Table 5)

x Private well PW-05 Only one of the 13 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within a range considered to pose a no apparent public health hazard Three other substances in the well had no available water CVs however all three had concentrations within ranges previously considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-05 were selected for further evaluation (Table 6)

x Private well PW-06 Two (duplicate) water samples were collected from well PW-06 In the first of the two samples none of the 12 substances detected in the sample exceeded any available water CVs Three of these substances had no available water CVs but all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 7) The second duplicate sample also showed that none of its 12 detected substances exceeded any available water CVs Again three of these substances had no available water CVs and all 3 showed measured concentrations within ranges considered not to pose a public health hazard (Table 8) Therefore none of the substances detected in PW-06 were selected for further evaluation

x Private well PW-07 None of the 10 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 9)

x Private well PW-08 Only one of the 12 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of the substances The concentrations of the 3 were within ranges considered to pose a no apparent public health hazard Therefore only the one substance bis(2-ethyhexyl)phthalate detected in well PW-08 was selected for further evaluation (Table 10)

4

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

x Private well PW-09 None of the 12 substances detected in this well exceeded the available water CVs however for 3 of these substances no water CVs were available The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 11)

x Private well PW-10 Only one of the 14 substances detected in this well showed levels that exceeded available water CVs The one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs still all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-10 were selected for further evaluation (Table 12)

x Private well PW-11 Only one of the 16 substances detected in this well showed levels that exceeded available water CVs This one substance did not require further public health evaluation because its measured concentration was within the range considered to pose a no apparent public health hazard Three of the substances in the well had no available water CVs however all three had concentrations within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in PW-11 were selected for further evaluation (Table 13)

x Private well PW-12 None of the 13 substances detected in this well exceeded the available water CVs however no water CVs were available for 3 of these substances The concentrations of all 3 were within ranges considered to pose a no apparent public health hazard Therefore none of the substances detected in this well were selected for further evaluation (Table 14)

Chemicals Selected for Further Public Health Analysis ATSDRrsquos review of the groundwater analyses of the private wells is summarized in Table 15 Using Table 15 our environmental health scientists selected certain substances detected in the private wells for further public health analysis These substances were categorized as exceeding available CVs or for which no CVs were available The following substances were selected for in-depth public health analysis

Substances Exceeding Drinking Water CVs

1) Nitrates 2) Vinyl Chloride 3) Bis(2-ethyhexyl)phthalate

Substances without Drinking Water CVs

None

Exposure Pathways Being that the residential community is comprised of long term residents and short term renters ATSDR determined that the exposures to the chemicals detected in the water samples were intermediate and chronic (ie moderate and long-term exposures respectively) that can occur via ingestion inhalation (VOCs) and dermal contact when groundwater is used for drinking showering and bathing or for other household purposes (NCDENR 1998 2000) Several studies

5

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

have indicated that exposures to VOCs can occur during showering and bathing as chemicals volatilize and enter the body through inhalation absorption or both Such exposures to VOCs may equal or exceed those from ingestion but usually by no more than a factor of 2 (Jo et al 1990 Kerger et al 2000 Kezic et al 1997 Mattie et al 1994 EPA 1999) Because of the low frequency of VOC detection (8) and the fact that only one (vinyl chloride) of the nine detected VOCs had a level that exceeded any available drinking water comparison values ATSDR considered VOC exposure through inhalation and skin absorption to be minimal or nonexistent Thus ingestion was the primary route of human exposure considered in this PHC Ingestion is also the route of exposure for other nonvolatile substances that were detected at a higher frequency (eg nitrates and metals)

Other Public Health Concerns The former site operators disposed of septic waste in the former lagoon area It remains there to this day raising concerns about the former lagoon area becoming an anaerobic (oxygenshydepleted) environment for the formation of hydrogen sulfide As part of the federally mandated cleanup that material from the former lagoons will be removed and transported to an appropriate hazardous waste treatment and disposal facility When removing the material from the former lagoons however it is possible that hydrogen sulfide may be released into the atmosphere which may place workers and those residents living next to the site at risk As a precaution during remediation and cleanup at the site necessary steps should be taken to prevent any possible exposures to hydrogen sulfide

Environmental health scientists from ATSDR visited the site in December 2005 and observed that private well PW-02 was inoperable and not in use Even though the well is not currently in use this does not restrict it from future use Because the well is inoperable and not in use ATSDR recommends that the well be properly capped and restricted from any future use past pre-2000 sampling has shown that the well contained nitrate levels as high as 23350 ppb If future use is planned for the well ATSDR recommends removal of all potential source areas at the site and to make necessary improvements in bringing well PW-02 water quality within safe drinking water standards

Past sampling data have shown that groundwater is probably flowing in a southerly to southwesterly direction (see Figure 4) Most recentlymdashin March 2006mdashgroundwater samples were collected from private wells in areas north east and west of the site however no samples were collected in the areas south to southwest of the site Past sampling data identified two problem wells in those areas PW-02 and PW-03 Both wells contained elevated levels of nitrates These nitrates pose a potential health risk to infants 6 months or younger and for the fetuses of pregnant women Therefore it may be wise to delineate further the groundwater underlying those areas south to southwest of the site

Public Health Implications After application of the selective screening criteria for this PHC three substances were selected for in-depth analysis That analysis is an integrated approach that studies site-specific exposures in conjunction with substance-specific toxicological medical and epidemiologic data (ATSDR 2005) The three substances were selected because their detected levels in well PW-03 and well

6

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

PW-08 exceeded available water CVs (See Appendix A for a description of comparison values and their proper interpretation)

Substances detected in the groundwater through the sampling of the private potable wells were screened with health-based comparison values (Tables 3-15) Health-based CVs represent those levels expected to be safe even for sensitive populations excluding hypersensitive (allergic) individuals Exceeding a CV does not indicate that adverse health effects are expected but it does reveal substances that may require additional evaluation of factors that influence the toxicity and likelihood of health effects Those substances exceeding CVs or for which comparison values do not exist were further evaluated for potential adverse health effects

That further evaluation as described below identified nitrates as the only substance for which intervention is recommended A nitrate level of 13000 ȝgL (ppb) was detected in one specific well This level exceeded EPArsquos maximum contaminant level (MCL) of 10000 ȝgL This level may be a cause of concern for infants 6 months or younger and for the fetuses of pregnant women

Nitrates The toxicity of nitrates is due to their conversion (reduction) to nitrites by bacteria in the gastrointestinal tract (ie intestines) These nitrites then combine with hemoglobin in the blood Once combined the nitrites convert the hemoglobin to methemoglobin a form of hemoglobin that cannot carry oxygen When enough hemoglobin is converted into methemoglobin the bloodrsquos ability to transport oxygen from the lungs to the tissues is impaired Infants are susceptible to methemoglobinemia because the higher pH (nonacidity) of their gastric juice is more compatible with the growth of nitrate-reducing bacteria in the gut Older children with their more acidic gastric juices are much less susceptible (Craun et al 1981) Probably the most important factor that makes infants more susceptible to methemoglobinemia is their inability to convert methemoglobin back to hemoglobin they lack the necessary levels of methemoglobin reductase a red-blood cell (RBC) enzyme which makes this metabolic transition possible Again adults and older children do tend to have the necessary levels of this RBC enzyme making them less susceptible The characteristic blueness (cyanosis) of lips and mucous membranes can be produced by methemoglobin levels between 20 and 45 (Clinical Toxicology 2001) Methemoglobin levels under 30 produce minimal symptoms (fatigue lightheadedness headache) in healthy children and adults while levels between 30 and 50 cause moderate depression of the cardiovascular and central nervous systems (eg weakness headache rapid breathing and heartbeat mild shortness of breath) Levels between 50 and 70 cause severe symptoms (eg stupor slow and abnormal heartbeat respiratory depression convulsions) and levels above 70 are usually fatal (Ellenhorn and Barceloux 1988) Any levels of methemoglobin that might be associated with the maximum detected nitrate levels in water from private wells at this site are likely to be less than 2 (See discussion below)

EPA has developed a chronic oral reference dose for the ingestion of nitrates based on the early clinical signs of methemoglobinemia (cyanosis) in infants ingesting water containing varying concentrations of nitrate-nitrogen That RfD is equivalent to the observed NOAEL (ie No Observed Adverse Effect Level) of 1600 ȝg nitrate-nitrogenkgday which is the dose that

7

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

would be received by a 0ndash3 month old infant weighing approximately 88 pounds (4 kg) and drinking 064 litersday of water (as formula) containing 10000 microgL nitrate-nitrogen

A primary source of organic nitrates is human sewage the processing of which formerly occurred at the site (ie removal and handling of septic wastes) Due to high solubility and weak retention in soil nitrates and nitrites are very soil-mobile and have a high potential to migrate to groundwater Most nitrogenous materials in natural waters tend to be converted to nitrate so all sources of combined nitrogen particularly organic nitrogen and ammonia should be considered as potential nitrate sources Because it does not volatilize nitratenitrite is likely to remain in water until consumed by plants or other organisms Ammonium nitrate will be taken up by bacteria Nitrate is more persistent in water than is the ammonium ion Nitrate degradation is fastest in anaerobic conditions (ie little to no oxygen present)

Nitrate was detected at a level above drinking water CVs in one private well PW-03 approximately 450 feet southwest of the site The estimated daily dose of nitrate from water containing 13000 ppb (maximum nitrate detection in Private Well PW3) would be 371 ȝgkgday for a 70-kg (ie 150 pounds) adult ingesting 2 liters of water per day 1300 ȝgkgday for a 10-kg (ie 20 pound) child ingesting 1 liter of water per day and 2080 ȝgkgday for a 4-kg (ie 8 pound) infant ingesting 064 liters of water (as formula) per day Although the estimated daily dose for a child is slightly higher than the RfD at these dose levels noncancerous health effects are not expected in adults or children older than 6 months Although chronic exposure to levels of nitrates that exceed EPArsquos RfD (in this case by a factor of 23) is not recommended for infants 1ndash3 months of age adverse effects would not be likely to occur in those infants either In one study oral doses of nitrate ranging from 100 ȝgkgday to 15500 ȝgkgday in 111 infants less than 6 months old was associated with methemoglobin levels as high as 53 (mean 16) but none of the children had the typical symptoms of methemoglobinemia (Winton et al 1971) In another study mean methemoglobin levels were only 13 in infants aged 1ndash3 months who received water containing 11000ndash23000 microg nitrate-nitrogenL (Simon et al 1964) Also no clinical signs of methemoglobinemia were detected in any of these infants Low levels of methemoglobin (05 to 20) occur normally and due to the large excess capacity of blood to carry oxygen levels of methemoglobin up to 10 are seldom associated with any clinically significant signs such as cyanosis (EPA-IRIS 2006) Most cases of infant methemoglobinemia are associated with exposure to nitrate in drinking water used to prepare infants formula at levels gt20000 ppb of nitrate-nitrogen Cases have been reported however at levels of 11000ndash20000 ppb nitrate-nitrogen especially when associated with concomitant exposure to bacteriologically contaminated water or excess intake of nitrate from other sources Therefore if other sources of drinking water are available well water from private well PW-03 should not be used for making infant formula

The findings from studies investigating the influence of nitrate on the reproductive outcomes in laboratory animals and livestock have not been consistent some studies do however suggest a possible connection between nitrate consumption and spontaneous abortions or miscarriages (Sund et al 1957 Sleight and Atallah 1968 FDA 1972) One epidemiologic study of humans has suggested a possible relation between ingestion of drinking water containing elevated nitrate levels and an increased risk for neural tube defects (Dorsch et al 1984) Yet another study

8

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

indicated a possible relation between methemoglobin levels in women during early pregnancy and subsequent spontaneous abortions (Schmitz 1961)

Public health scientists investigated this possible link between spontaneous abortions and the ingestion of nitrate-contaminated well water (MMWR 1996) During March 1993 the LaGrange County (Indiana) Health Department (LCHD) identified three women who reported a total of six spontaneous abortions during 1991ndash1993 and who resided in close proximity to each other Each of the three women had obtained drinking water from nitrate-contaminated private wells in LaGrange County Nitrate was the only well contaminant present at elevated levels In the wells from which the three women drank nitrate levels were 19000 ȝgL 26000 ȝgL and 19200 ȝgL In comparison for five households in which women reported giving birth to full-term liveshyborn infants drinking water nitrate levels ranged from 1600 ȝgL to 8400 ȝgL (mean 31 ȝgL) An investigation of potential sources of nitrate contamination indicated that the probable source of groundwater contamination was animal waste from a hog-confinement facility The facility was approximately frac12 to 1 mile from the residences of the women who experienced spontaneous abortions the facility was however approximately 2 miles from the residences of the women reporting full-term births

Subsequently LCHD was notified about a fourth case in which a woman from another part of LaGrange County had two spontaneous abortions after she had moved into a new home with a nitrate-contaminated private well The woman age 35 lived approximately 10 miles from the other three women During 1984ndash1992 she gave birth to five live infants But the womanrsquos doctor also reported to LCHD that the woman had two spontaneous abortions during April and August 1994 both at 8 weeksrsquo gestation the first occurred 24 months after the birth of her fifth child and 44 months after beginning use of a new well A mean nitrate-Nitrogen level of 28700 microgL was detected in water samples collected during August 1994 from the householdrsquos well which had been used since 1990 A nitrate-Nitrogen level of 1200 microgL was detected in a second well on the property approximately 100 feet from the first well during her first four pregnancies this well had supplied the womanrsquos drinking water The only nitrate source identified near the contaminated well was the familyrsquos septic system which was installed in sandy soil approximately 70 feet upgradient from the contaminated well Although the well probably became contaminated by effluent from the septic tank when that contamination occurred is unknown

Following the investigations all four women changed to nitrate-free sources of drinking water (ie bottled or reverse-osmosis treated) Subsequently each delivered one or more full-term live infants

Vinyl Chloride Vinyl chloride was only detected in one private well PW-03 with an estimated value of 021 microgL This concentration is one order of magnitude (or 10 times) lower than the MCL of 20 ȝgL which is set at a conservatively low level to protect the health of sensitive individuals such as children and the elderly The detected level of vinyl chloride exceeded only one water CV ATSDRrsquos cancer risk evaluation guide (CREG) The CREG and other similar CVs are the most conservative of long-term health benchmarks given that they are based on estimates of theoretical cancer risk The level of vinyl chloride detected in well PW-03 would correspond to a

9

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

dose of 0021 micrograms per kilogram per day (microgkgday) for a 10-kilogram (kg) child drinking 1 liter of water per day (Lday) and 0006 microgkgday for a 70-kg adult drinking 2 Lday Both values are well below EPArsquos reference dose of 3 microgkgday (A reference dose is an estimate of daily exposure to a contaminant unlikely to cause noncancer adverse health effects) No drinking water studies of vinyl chloride exposure have been conducted in either humans or animals given the high volatility and low water solubility of vinyl chloride ingestion of drinking water is not a toxicologically effective route of exposure for this compound To deliver toxic oral doses to laboratory animals investigators must administer vinyl chloride in oil by gavage or in a diet containing PVC powder It is from such animal studies that EPA derived its chronic oral reference dose (RfD) of 3 microgkgday

Taking into consideration supporting evidence for carcinogenesis cancer-based CVs for ingesting vinyl chloride or any carcinogen are derived using the methodology of quantitative risk assessments The methodology of quantitative risk assessments usually employs EPAs cancer slope factors (CSFs) and inhalation unit risks (IURs) CSFs and IURs are computed on the basis of two limiting assumptions 1) zero-threshold for carcinogens and 2) low-dose linearity Zero-threshold incorporates the assumption that the process of chemical carcinogenesis can cause cancer and can have an associated cancer risk at any exposure no matter how small or low the dosemdasheven doses approaching zero (Bogdanffy et al 2001) Moreover low-dose linearity incorporates the assumption that in the low-dose region of a dose-response curve (ie the graphical display of cancer incidence observed over a range of chemical doses in animal or occupational studies) the rate of change between the carcinogenic response and chemical dose approaches a constant and behaves linearly even down to zero dose Using statistical models a mathematical equation of a straight line can be developed to approximate the linear relationship of the low-dose region of the dose-response curve The slope of the resulting straight line is called a CSF (for dose data) or IUR (for air concentration data) And the straight line can be extrapolated to any dose or water concentrationmdashno matter how smallmdashto give a corresponding estimate of cancer risk Because no actual data points exist in the region of extrapolation (ie estimated risks of 10-4 and less) these estimates of cancer risk are theoretical and may not reflect the true or actual risk which is in fact unknown and may be as low as zero (EPA 1986 2003)

Vinyl chloride is a known human carcinogen only under certain circumstances Vinyl chloride has been consistently associated with elevated incidences of rare angiosarcomas of the liver in humans but only by inhalation and only at the extremely high worker exposures that were once associated with certain job categories that no longer exist (Zocchetti 2001) This same form of liver cancer has also been produced experimentally in rats treated with chronic oral doses of 300 microgkgday In humans this dose would be numerically (if not biologically) equivalent to 10500 microgL in drinking water for an adult drinking for several decades 2 Lday or 3000 microgL for a child drinking 1 Lday over a similar time period These toxic levels are 14300 to 50000 times higher than the detected level of vinyl chloride in private well PW-03 (ie greater than four orders of magnitude)

Because the level of vinyl chloride did not exceed any CVs for noncancer effects and was not detected in the other private wells ATSDR concludes that the vinyl chloride detected in private well PW-03 does not pose a public health hazard to anyone drinking water from it

10

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Bis(2-ethyhexyl)phthalate (DEHP) DEHP was detected in only one private well (PW-08) and at a concentration (62 microgL)mdash practically indistinguishable from the MCL of 6 microgL ATSDRrsquos chronic Minimum Risk Level (MRL) for DEHP is 60 microgkgday ATSDRrsquos chronic MRLs are derived human no-effect levels (expressed as doses) that are designed to be conservatively protective against noncancer health effects for exposure durations of more than 1 year up to an entire lifetime Assuming a 70-kg adult drinks 2 liters of water a day and a 10-kg child drinks 1 liter of water a day the 60 microgkgday MRL for DEHP converts to ATSDRrsquos adult and child chronic drinking water EMEGs of 2000 ugL and 600 microgL respectively Therefore ATSDRrsquos chronic drinking water EMEGS for DEHP exceed by two or more orders of magnitude the only level of DEHP detected in private wells water surrounding the site This indicates that DEHP poses no noncancer hazard

Under default conditions of exposure over a lifetime a CREG coincides with a theoretical 1-inshya-million risk of cancer in humans ATSDRrsquos CREG of 3 ppb was the only one of ATSDRrsquos CVs in which the single detect of 62 ppb did in fact exceed Nevertheless neither this nor any other plausible concentration of DEHP in drinking water is likely to yield a carcinogenic dose in humans Most supporting evidence (ie animal studies) does not show a causal relationship between DEHP exposure and cancer in humans First the spontaneous incidence of liver tumors in rodents can be as much as 1ndash2 orders of magnitude higher than it is in humans (Compare Derelanko amp Hollinger 1995 and SEER Cancer Statistics Review 1975ndash2003) which means that high doses of a nongenotoxic promoting agent like DEHP will generally speaking promote many more spontaneously initiated cells in rodents than the same concentrations ever could in humans Second statistically significant increases in the lifetime incidence of liver tumors can be produced in rodents only by high environmentally irrelevant doses of DEHP (ie hundreds or thousands of mgkgday for life) which are 3ndash4 orders of magnitude higher than human exposures in the general population (ATSDR 2002b) Even the highest short-term human exposures (ie up to an estimated 2ndash3 mgkgday in hemodialysis patients) are 2ndash3 orders of magnitude higher than the lifelong daily doses required to produce liver cancer in rodents (ATSDR 2002b) Finally DEHP evidently produces excess rodent liver tumors via a nongenotoxic species-specific mechanism (ie induction of peroxisome proliferation by the monoester metabolite MEHP) which is irrelevant to human beingsmdashldquohumans are nonshyresponsive to peroxisome proliferationrdquo (ATSDR 2002b) Thus even if humans had the same spontaneous incidence of liver tumors as do rodents and chronic human doses of hundreds or even thousands of mgkgday were possible DEHP would still not cause cancer in humans at least not by the same mechanism that pertains in animals

Therefore ATSDR concludes that the single detect of 62 microgL in a private well PW-08 does not pose a public health hazard

Child Health Considerations ATSDR considers children in the evaluation for all environmental exposures and uses health guidelines that are protective for children When evaluating any potential health effects via ingestion children are considered a special or sensitive population Because of their lower body weight the same exposure will result in a higher dose as compared to adults ATSDRs child

11

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

EMEGs take into account average body weight differences as well as average differences in child-specific intake rates for various environmental media

The April 2005 delineation investigation showed an elevated level of nitrates in one private well located approximately 450 feet southwest of on-site source areas The level was high enough to pose an increased risk of elevated methemoglobin levels in very young infants (less than 6 months of age) who drank formula prepared with this water Another group at similar risk is pregnant females drinking the tainted water could adversely affect their fetuses ATSDR has evaluated this site in the past and has written several PHCs ATSDR again recommends that with regard to those households whose wells have been affected by nitrates or by other substances that perhaps migrated from the site such households should be supplied with an alternative water source (bottled water or municipal water) or have installed a water filtrationpurification system that yield safe drinking water

Conclusions 1 During the April 2005 delineation investigation at the Sigmon Septic Tank Service Site

private well PW-03 showed nitrate levels of 13000 ppb This detected level posed an increased risk of higher methemoglobin levels in very young infants (0ndash6 months) drinking formula prepared with water from this well The sensitive population also included pregnant females who drank water from this well which could adversely affect their fetuses

2 The vinyl chloride concentration detected in private well PW-03 pose no apparent public health hazard to residents however drinking water from private well PW-03 did pose a potential health concern to two sensitive subgroups very young infants (0ndash6 months) and pregnant females if they used the water from the well (ie not because of the detected vinyl chloride level but because of the detected level of nitrates refer to conclusion 1) Moreover the detected level of bis(2-ethyhexyl)phthalate in private well PW-08 pose no apparent public health hazard to residents using water from the well

Recommendations 1 Supply an alternative water source (bottled water) or implement another remedy (eg

installation of a water filtrationpurification system) that yields potable water within safe drinking water standards to households whose private wells are impacted by nitrates or other substances that could have migrated from the site Continue this responsive action until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

2 Consider removing the source areas from the Sigmon Septic Tank Service facility to reduce prevent or both any potential migration of hazardous substances into nearby private wells

3 Consider properly capping private well PW-02 if no future use is intended for the well

12

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

4 Implement within health safety plan appropriate actions of preventing any possible exposures to hydrogen sulfide during remediation and cleanup at the site

5 Continue routinely to collect and analyze groundwater samples particularly for nitrates and lead from both the monitoring wells and from nearby private wells (notably in the area of private wells PW-02 and PW-03) until the appropriate investigations are completed strategies formulated remedial actions implemented and local water supplies are brought within safe drinking standards

Public Health Action Plan 1 Follow up with EPA in educating and informing concerned residents about the public

health importance of using an alternative water source (bottled water) or implementing another remedy (installation of a water filtrationpurification system) that yields safe drinking water until further notified that their own water is within safe drinking water standards

13

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Authors

David S Sutton PhD PE

Environmental Health Scientist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Frank C Schnell PhD DABT

Senior Toxicologist

Exposure Investigations Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Reviewers

Susan Moore

Branch Chief

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Peter Kowalski MPH CIH

Lead Environmental Health Specialist

Site Assessment Team

Exposure Investigations and Site Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

14

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Kenneth Orloff PhD DABT

Assistant Director of Science

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Annmarie K DePasquale MPH

Environmental Health Scientist

Site Assessment Team C

Site and Radiological Assessment Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Januett P Smith-George MSW

Senior Program Management Officer

Team A

Health Promotion and Community Involvement Branch

Division of Health Assessment and Consultation

Agency for Toxic Substances and Disease Registry

Benjamin Moore MS

Regional Representative

Region IV

Division of Regional Operations

Agency for Toxic Substances and Disease Registry

Wallace K Sagendorph JD

Writer Editor

Office of Communication

National Center for Environmental Health

and Agency for Toxic Substances and Disease Registry

15

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

References [ATSDR] Agency for Toxic Substances and Disease Registry 2002a Health consultation

Review of groundwater data Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2002 March 29

[ATSDR] Agency for Toxic Substances and Disease Registry 2002b Toxicological profile for di(2-ethylhexyl)phthalate (DEHP) Atlanta US Department of Health and Human Services 2002 September

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Public Health Assessment Guidance Manual (Update) Atlanta Agency for Toxic Substances and Disease Registry US Department of Health and Human Services 2005 January

[ATSDR] Agency for Toxic Substances and Disease Registry 2006 Health consultation Review of groundwater data (2002 and 2004 EPA delineation investigations) Sigmonrsquos Septic Tank Service facility Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services 2006 April 3

Black amp Veatch Black amp Veatch Special Projects Corporation 2004 Final data evaluation report (2004 update) Sigmonrsquos Septic Tank Site Statesville Iredell County North Carolina Prepared for the United States Environmental Protection Agency Region 4 EPA Work Assignment Number 340-RICO-A44F BVSPC Project Number 48340 18 October

Bogdanffy MS Daston G Faustman EM Kimmel CA Kimmel GL Seed J et al 2001 Harmonization of cancer and noncancer risk assessment proceedings of a consensus-building workshop Toxicol Sci 6118ndash31

Bosch HM Rosefield AB Huston R Shipman HR Woodward FL 1950 Methemoglobinemia and Minnesota well supplies J Am Water Works Assoc 42161ndash70

Clinical Toxicology 2001 Ford Delaney Ling and Erickson Eds New York NY WB Saunders Co

Craun GF Greathouse DG Gunderson DH 1981 Methemoglobin levels in young children consuming high nitrate well water in the United States Int J Epidemiol 10(4)309ndash17

CRC Handbook of Toxicology Derelanko MJ and Hollinger MA Eds New York NY CRC Press Inc 1995

Dorsch MM Scragg RKR McMichael AJ Baghurst PA Dyer KF 1984 Congenital malformations and maternal drinking water supply in rural South Australia a case-control study J Epidemiol 119473ndash86

Ellenhorn MJ and Barceloux DG 1988 Medical Toxicology diagnosis and treatment of human poisoning New York NY Elsevier Science Publishing Company Inc p 849

[EPA] US Environmental Protection Agency 1986 Guidelines for carcinogenic risk assessment Washington DC Federal Register 51(185) 33992ndash34003 1986 September 24

[EPA] US Environmental Protection Agency 1990 Criteria document for nitratenitrite Washington DC Office of Drinking Water

16

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

[EPA] US Environmental Protection Agency 1997 Environmental investigations standard operating procedures and quality assurance manual (EISOPQAM) 1996 (revised 1997) Washington DC Environmental Services Division May

[EPA] US Environmental Protection Agency 1999 Risk assessment guidelines for dermal assessment Washington DC

[EPA] US Environmental Protection Agency 2003 Draft final guidelines for carcinogen risk assessment final (external review draft) Risk Assessment Forum Washington DC NCEA-F-0644A March

[EPA] US Environmental Protection Agency Integrated risk information system Cincinnati US Environmental Protection Agency Office of Health and Environmental Assessment Available at httpwwwepagoviriswebpirisindexhtml [Accessed 2006 May 3]

[FDA] Food and Drug Administration Teratologic evaluation of FDA 71-7 (sodium nitrate) Washington DC US Department of Health and Human Services Public Health Service Food and Drug Administration publication no PB 221775 1972

Jo WK Weisel CP Lioy PJ 1990 Routes of chloroform exposure and body burden from showering with chlorinated tap water Risk Anal 10575ndash580

Kerger BD Schmidt CE Paustenbach DJ 2000 Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths Risk Anal 20637ndash651

Kezic S Mahieu K Monster AC de Wolff FA 1997 Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers Occup Environ Med 5438ndash43

Mattie DR Bates GD Jr Jepson GW Fisher JW McDougal JN 1994 Determination of skin-air partition coefficients for volatile chemicals experimental method and applications Fundam Appl Toxicol 2251

[MMWR] Morbidity and Mortality Weekly Report 1996Spontaneous abortions possibly related to ingestion of nitrate-contaminated well watermdashLaGrange County Indiana 1991ndash1994 Atlanta Centers for Disease Control and Prevention US Department of Health and Human Services MMWR 1996 45(26)569ndash72

Muhrer ME Garner GB Pfander WH et al 1959 The effect of nitrate on reproduction and lactation J An Sci 151291ndash2

[NCDENR] North Carolina Department of Environment and Natural Resources 1998 Combined preliminary assessmentsite inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 06611 Raleigh Division of Waste Management Superfund Section 1998 September

[NCDENR] North Carolina Department of Environment and Natural Resources 2000 Expanded site inspection report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Reference No 0406611 Raleigh Division of Waste Management Superfund Section 2000 March

Schmitz JT 1961 Methemoglobinemia cause of abortions Obstet Gynecol 17413ndash5 SEER Cancer Statistics Review 1975ndash2003

17

Simon CH Manzke H Kay H Mrowetz G 1964 Uumlber Vorkommen Pathogenese und Moumlglichkeiten zur Prophylaxe der durch Nitrit versuchteten Methaumlmoglobinaumlmie [Occurrence pathogenesis and possible prophylaxis of nitrite-induced methemoglobinemia] Z Kinderheilk 91124ndash38

Sleight SD and Atallah OA 1968 Reproduction in the guinea pig as affected by chronic administration of potassium nitrate and potassium nitrite Toxicol Appl Pharmacol 12179B185

Sund J Wright MJ Simon J Weeds containing nitrate cause abortion in cattle Agron J 195749278ndash9

Walton G 1951 Survey of literature relating to infant methemoglobinemia due to nitrate-contaminated water Am J Pub Health 41986996

Winton EF Tardiff RG McCabe LJ 1971 Nitrate in drinking water J Am Water Works Assoc 6395ndash98

Zocchetti C 2001 Liver angiosarcoma in humans epidemiological considerations Med Lav 2001 Jan-Feb 92(1)39-53 (Italian) English abstract of this review article is available online at httpwwwncbinlmnihgoventrezqueryfcgicmd=Retrieveampdb=pubmedampdopt=Abstract amplist_uids=11367826ampquery_hl=1ampitool=pubmed_DocSum

Selected Bibliography Accu-Chem Chlorinated pesticides screening test fact sheet Richardson TX Accu-Chem

Laboratories Available at httpwwwaccuchemcomtoxtestpanelsdatasheetscpstfactsheethtm [Accessed 2006 March 16]

Andelman JB 1990 Total exposure to volatile organic compounds in potable water In Ram NM Christman RF Cantor KP Eds Significance and treatment of volatile organic compounds in water supplies Chelsea MI Lewis Publishers p 485ndash504

Arbuckle TE Sherman GJ Corey PN Walters D Lo B 1988 Water nitrates and CNS birth defects a population-based case-control study Arch Environ 43(2)162ndash67

[ATSDR] Agency for Toxic Substances and Disease Registry 1992 Toxicological profile for 2shyhexanone Atlanta US Department of Health and Human Services September

[ATSDR] Agency for Toxic Substances and Disease Registry 1993 Toxicological profile for heptachlor and heptachlor epoxide Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 1994 Toxicological profile for chlordane Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 1996 Toxicological profile for endrin Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 1997 ToxFAQs for endrin and endrin aldehyde Atlanta US Department of Health and Human Services Available at httpwwwATSDRcdcgovtfacts89html

18

[ATSDR] Agency for Toxic Substances and Disease Registry 1999a Toxicological profile for hexane Atlanta US Department of Health and Human Services 1999 July

[ATSDR] Agency for Toxic Substances and Disease Registry 1999b Toxicological profile for lead Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 2000 Toxicological profile for arsenic Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 2001a Record of activity site visit report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services July 11

[ATSDR] Agency for Toxic Substances and Disease Registry 2001b Record of activity site visit report Sigmonrsquos Septic Tank Service (CERCLIS No NCD062555792) Statesville Iredell County North Carolina Atlanta US Department of Health and Human Services September 26

[ATSDR] Agency for Toxic Substances and Disease Registry 2003 Toxicological profile for zinc Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 2003 Toxicological profile for hexachlorocyclohexanes (HCH) Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 2004 Toxicological profile for copper mdash draft for public comment Atlanta US Department of Health and Human Services

[ATSDR] Agency for Toxic Substances and Disease Registry 2005 Drinking Water Comparison Value Table Atlanta US Department of Health and Human Services 2005 March 31

Cattley RC DeLuca J Elcombe C et al 1998 Do peroxisome proliferating compounds pose a hepatocarcinogenic hazard to humans Reg Toxicol Pharmacol 2747ndash60

[EPA] US Environmental Protection Agency1991 National primary drinking water regulations Washington DC Code of Federal Regulations

[EPA] US Environmental Protection Agency 1996 Drinking water regulations and health advisoriesWashington DC Office of Water 822-B-96-002

[EPA] US Environmental Protection Agency 1998 Safe drinking water fact sheet for nitrate Available at httpwww[EPA]goviriswebpirissubst0076htm [accessed 2006 March 21]

[EPA] US Environmental Protection Agency 2001 Review of adult lead models evaluation of models for assessing human health risks associated with lead exposures at non-residential areas of superfund and other hazardous waste sites Available at httpwww[EPA]govsuperfundprogramsleadproductshtm 2001 May 8 [accessed 2006 March 21]

[EPA] 2001 Risk-based concentration table Philadelphia US Environmental Protection Agency Region III Office May 8 2001

[EPA] 2004a Region 6 Human health medium-specific screening levels Washington DC US Environmental Protection Agency

19

[EPA] 2004b Region 9 Preliminary remediation goals Washington DCUS Environmental Protection Agency

Huber WW Grasl-Kraupp B Schulte-Herman R 1996 Hepatocarcinogenic potential of di(2shyethylhexyl)phthalate in rodents and its implications on human risk Crit Rev Toxicol 26365ndash 481

[IARC] International Agency for Research on Cancer 1979 Some halogenated hydrocarbons Chlordane Monographs on the evaluation of the carcinogenic risk of chemicals to man Geneva World Health Organization vol 20 p 45ndash65

Lake BG 1995 Mechanisms of hepatocarcinogenicity of peroxisome-proliferating drugs and chemicals Ann Rev Pharmacol Toxicol 35483ndash507

Merck 2001 The Merck Index 13th edition Whitehouse Station Merck and Co I nc p 634 [NIOSH] National Institute for Occupational Safety and Health 1995 Documentati on for

immediately dangerous to life or health concentrations (IDLHs) NIOSH chemi cal listing and documentation of revised IDLH values (as of 3195) Cincinnati Available at httpwwwcdcgovnioshintridl4html [Accessed 2006 March 16]

NIOSH National Institute for Occupational Safety and Health The registry of toxic effects of chemical substances (RTECS) Yttrium Trioxide from NIOSH Spassky SS (1978) Toxicity of yttrium oxide The registry of toxic effects of chemical substances (RTECS) Yttrium Trioxide from NIOSH Gig Tr Prof Zabol 22(7)5560 [in Russian] Cincinnati Available at httpwwwcdcgovnioshidlh7440655html [Accessed 2006March 20]

[NRC] National Research Council 1980 Drinking water and health Washington DC National Academy Press vol 3

OSHAOccupational Safety and Health Guideline for Yttrium and Compounds Available at httpwwwoshagovSLTChealthguidelinesyttriumandcompoundsrecognitionhtml

[Accessed 2006 March 16] Salvato JA 1992 Environmental engineering and sanitation 4th edition Chapter 3 Water

supply New York John Wiley amp Sons Inc Topping DC Morgott DA ODonoghue JL 2001 Ketones of six to thirteen carbons In

Bingham E Cohrssen B Powell CH Eds Pattys toxicology 5th edition vol 6 Hoboken NJ John Wiley amp Sons Inc Available at httpelib2cdcgov2082pattystoxarticlestox076framehtml [Accessed 2006 March 20]

Webster RC Mobayen M Maibach HI 1987 In vivo and in vitro absorption and binding to powdered stratum corneum as methods to evaluate skin absorption of environmental chemical contaminants from ground and surface water J Toxicol Eviron Health 21367ndash74

20

Appendix A Comparison Values ATSDR comparison values (CVs) are media-specific concentrations that are considered to be safe under default conditions of exposure They are used as screening values in selecting site-specific chemicals for further evaluation of their public health implications Generally a chemical is selected for further public health evaluation because its maximum concentration in air water or soil at the site exceeds at least one of ATSDRrsquos CVs Supplementing this conservative approach is ATSDRrsquos guidance that requires environmental health scientists to exercise professional judgment when selecting chemicals for further public health evaluation evaluating exposure pathways and determining the public health implications of site-specific exposures (ATSDR 1992) ATSDR may also select detected chemical substances for further public health evaluation and discussion because ATSDR has no CVs for certain specified chemicals or because the community has expressed special concern about the substance whether it exceeds CVs or not

It must be emphasized that CVs are not thresholds of toxicity While concentrations at or below the relevant CV are generally considered to be safe it does not automatically follow that any environmental concentration that exceeds a CV would be expected to produce adverse health effects In fact the whole purpose behind highly conservative health-based standards and guidelines is to enable health professionals to recognize and resolve potential public health problems before they become actual health hazards For that reason ATSDRrsquos CVs are typically 1 to 3 orders of magnitude (10ndash1000 times) lower than the corresponding no-effect levels or lowest-effect levels on which they are based The probability that adverse health outcomes will actually occur depends not on environmental concentrations alone but on several additional factors including site-specific conditions of exposure individual lifestyle and genetic factors affecting the route magnitude and duration of actual exposures and individual physiological responses to those exposures

Listed below are the abbreviations for selected CVs and units of measure used within this document Following this list of abbreviations are more complete descriptions of the various comparison values used within this document as well as a brief discussion on one of ATSDRrsquos most conservative CVs

CREG = cancer risk evaluation guide

EMEG = environmental media evaluation guide

LTHA = drinking water lifetime health advisory

MCL = maximum contaminant level

MCLA = maximum contaminant level action

MRL = minimal risk level

RBC = risk-based concentration

RfD = reference dose

RMEG = reference dose media evaluation guide

A-1

Units of measure

ppm = parts per million eg mgL (water) mgkg (soil)

ppb = parts per billion eg PgL (water) Pgkg (soil)

ppt = parts per trillion eg ngL (water)

kg = kilogram (1000 grams)

mg = milligram (0001 gram)

Pg = microgram (0000001 gram)

ng = nanogram (0000000001 gram)

L = liter (1000 milliliters or 1057 quarts of liquid or 0001 m3 of air)

m3 = cubic meter (a volume of air equal to 1000 liters)

Cancer risk evaluation guides (CREGs) are derived by ATSDR They are estimated chemical concentrations theoretically expected to cause no more than one excess case of cancer per million people exposed over a lifetime CREGs are derived from EPArsquos cancer slope factors and therefore reflect estimates of risk based on the assumption of zero threshold and lifetime exposure Such estimates are necessarily hypothetical As stated in EPArsquos 1986 Guidelines for Carcinogenic Risk Assessment (EPA 1986) ldquothe true value of the risk is unknown and may be as low as zerordquo

Drinking water equivalent levels (DWELs) are lifetime exposure levels specific for drinking water (assuming that all exposure is from that medium) at which adverse noncarcinogenic health effects would not be expected to occur They are derived from EPA reference doses (RfDs) by factoring in default ingestion rates and body weights to convert the RfD to an equivalent concentration in drinking water

Minimal risk levels (MRLs) are ATSDR estimates of daily human exposures to a chemical that are unlikely to be associated with any appreciable risk of deleterious noncancer effects over a specified duration of exposure MRLs are calculated with data from human and animal studies and are reported for acute (lt14 days) intermediate (15ndash364 days) and chronic (gt365 days) exposures MRLs for oral exposure ingestion) are doses typically expressed in mgkgday Inhalation MRLs are concentrations typically expressed in either parts per billion (ppb) or Pgm3

(ppt or parts per trillion) The latter are identical to ATSDRrsquos EMEGs for airborne contaminants ATSDRrsquos MRLs are published in ATSDR toxicological profiles for specific chemicals

Environmental media evaluation guides (EMEGs) are media-specific concentrations that are calculated from ATSDRs Minimal Risk Levels by factoring in default body weights and ingestion rates Different EMEGs are calculated for adults and children as well as for acute (lt14 days) intermediate (15ndash364 days) and chronic (gt365 days) exposures

EPA reference dose (RfD) is an estimate of the daily exposure to a contaminant unlikely to cause any noncarcinogenic adverse health effects over a lifetime of chronic exposure Like the ATSDR MRL the EPA RfD is a dose and is typically expressed in mgkgday

A-2

Reference dose media evaluation guide (RMEG) is the concentration of a contaminant in air water or soil that ATSDR derives from EPArsquos RfD for that contaminant by factoring in default values for body weight and the media-specific intake rate Like ATSDR EMEGs RMEGs are calculated for both adults and children

Risk-based concentrations (RBCs) are media-specific values derived by the Region III Office of the US Environmental Protection Agency from EPA RfDs RfCs or cancer slope factors by factoring in default values for body weight exposure duration and ingestioninhalation rates These values represent levels of chemicals in air water soil and fish that are considered safe over a lifetime of exposure RBCs for noncarcinogens and carcinogens are analogous to ATSDR EMEGs and CREGs respectively

Lifetime health advisories (LTHAs) are calculated from the drinking water equivalent level (DWEL) and represent the concentration of a substance in drinking water estimated to have negligible deleterious effects in humans over a lifetime of 70 years assuming 2 liter per day water consumption for a 70-kilogram adult In the absence of chemical-specific data LTHAs are 20 and 10 of the corresponding DWELs for noncarcinogenic organic and inorganic compounds respectively LTHAs are not derived for compounds that are potentially carcinogenic for humans

Maximum contaminant levels (MCLs) are drinking water standards established by the EPA They represent levels of substances in drinking water that EPA deems protective of public health over a lifetime (70 years) at an adult exposure rate of 2 liters of water per day They differ from other protective comparison values in that they (1) reflect consideration of both carcinogenic and noncarcinogenic effects (2) take into account the availability and economics of water treatment technology and (3) are legally enforceable

Maximum contaminant level action (MCLA) are action levels for drinking water set by EPA under Superfund When the relevant action level is exceeded a regulatory response is triggered

When screening individual chemical substances ATSDR staff compares the highest single concentration of a chemical detected at the site with the appropriate CV available for the most sensitive of the potentially exposed individuals (usually children) Typically the cancer risk evaluation guide (CREG) or chronic environmental media evaluation guide (cEMEG) is used This worst-case approach introduces a high degree of conservatism into the analysis and often results in the selection of many chemical substances for further public health evaluation that upon closer scrutiny will not be judged to pose any hazard to human health In the interest of public health it is however more prudent to use an environmental screen that identifies many chemicals for further evaluation that may later be determined to be harmless as opposed to one that may overlook even a single potential hazard to public health The reader should keep in mind the conservativeness of this approach when interpreting ATSDRrsquos analysis of the potential health implications of site-specific exposures

A-3

Appendix B Tables

B-1

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n IN

OR

GA

NIC

MO

ITIE

S N

itrat

es

100

-- 2

335

0 8

164

860

0 P

oten

tial P

ublic

Hea

lth C

once

rn

Sul

fate

s 6

000

600

0 6

000

No

App

aren

t Pub

lic H

ealth

Haz

ard

MET

ALS

A

lum

inum

20

0 --

17

00

950

950

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bar

ium

16

-- 4

00

164

90

No

App

aren

t Pub

lic H

ealth

Haz

ard

Cal

cium

21

000

-- 9

500

0 58

000

58

000

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 1

2 --

26

2

1 2

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r 14

-- 6

0 37

6

38

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron

14 --

55

00

173

6 19

5 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Le

ad

2 --

28

89

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mag

nesi

um

160

0 --

12

000

698

3 7

250

No

App

aren

t Pub

lic H

ealth

Haz

ard

Man

gane

se

42

-- 8

30

153

1 78

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ercu

ry

1 --

7

28

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Nic

kel

23

-- 4

2

325

3

25

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um

130

0 --

70

00

299

0 2

150

No

App

aren

t Pub

lic H

ealth

Haz

ard

Sod

ium

5

300

-- 1

500

0 10

150

10

150

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Zi

nc

28 --

25

00

541

155

No

App

aren

t Pub

lic H

ealth

Haz

ard

OR

GA

NIC

CO

MPO

UN

DS

Ace

tone

5

-- 2

33

719

47

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ben

zene

0

4 0

4 0

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

rom

odic

hlor

omet

hane

3

3 3

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

04

04

04

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

0

6 --

39

134

6 0

78

No

App

aren

t Pub

lic H

ealth

Haz

ard

Dib

rom

ochl

orom

etha

ne

1 1

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

03

-- 4

8 24

24

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

4-D

ichl

orob

enze

ne

027

-- 4

4 3

91

077

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

1-D

ichl

oroe

than

e 0

4 --

15

0

7 0

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

oroe

than

e 0

53

053

0

53

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

043

-- 3

5

13

08

No

App

aren

t Pub

lic H

ealth

Haz

ard

Met

hyle

ne C

hlor

ide

2 2

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d

B-2

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

Units of measure

ppm = parts per million eg mgL (water) mgkg (soil)

ppb = parts per billion eg PgL (water) Pgkg (soil)

ppt = parts per trillion eg ngL (water)

kg = kilogram (1000 grams)

mg = milligram (0001 gram)

Pg = microgram (0000001 gram)

ng = nanogram (0000000001 gram)

L = liter (1000 milliliters or 1057 quarts of liquid or 0001 m3 of air)

m3 = cubic meter (a volume of air equal to 1000 liters)

Cancer risk evaluation guides (CREGs) are derived by ATSDR They are estimated chemical concentrations theoretically expected to cause no more than one excess case of cancer per million people exposed over a lifetime CREGs are derived from EPArsquos cancer slope factors and therefore reflect estimates of risk based on the assumption of zero threshold and lifetime exposure Such estimates are necessarily hypothetical As stated in EPArsquos 1986 Guidelines for Carcinogenic Risk Assessment (EPA 1986) ldquothe true value of the risk is unknown and may be as low as zerordquo

Drinking water equivalent levels (DWELs) are lifetime exposure levels specific for drinking water (assuming that all exposure is from that medium) at which adverse noncarcinogenic health effects would not be expected to occur They are derived from EPA reference doses (RfDs) by factoring in default ingestion rates and body weights to convert the RfD to an equivalent concentration in drinking water

Minimal risk levels (MRLs) are ATSDR estimates of daily human exposures to a chemical that are unlikely to be associated with any appreciable risk of deleterious noncancer effects over a specified duration of exposure MRLs are calculated with data from human and animal studies and are reported for acute (lt14 days) intermediate (15ndash364 days) and chronic (gt365 days) exposures MRLs for oral exposure ingestion) are doses typically expressed in mgkgday Inhalation MRLs are concentrations typically expressed in either parts per billion (ppb) or Pgm3

(ppt or parts per trillion) The latter are identical to ATSDRrsquos EMEGs for airborne contaminants ATSDRrsquos MRLs are published in ATSDR toxicological profiles for specific chemicals

Environmental media evaluation guides (EMEGs) are media-specific concentrations that are calculated from ATSDRs Minimal Risk Levels by factoring in default body weights and ingestion rates Different EMEGs are calculated for adults and children as well as for acute (lt14 days) intermediate (15ndash364 days) and chronic (gt365 days) exposures

EPA reference dose (RfD) is an estimate of the daily exposure to a contaminant unlikely to cause any noncarcinogenic adverse health effects over a lifetime of chronic exposure Like the ATSDR MRL the EPA RfD is a dose and is typically expressed in mgkgday

A-2

Reference dose media evaluation guide (RMEG) is the concentration of a contaminant in air water or soil that ATSDR derives from EPArsquos RfD for that contaminant by factoring in default values for body weight and the media-specific intake rate Like ATSDR EMEGs RMEGs are calculated for both adults and children

Risk-based concentrations (RBCs) are media-specific values derived by the Region III Office of the US Environmental Protection Agency from EPA RfDs RfCs or cancer slope factors by factoring in default values for body weight exposure duration and ingestioninhalation rates These values represent levels of chemicals in air water soil and fish that are considered safe over a lifetime of exposure RBCs for noncarcinogens and carcinogens are analogous to ATSDR EMEGs and CREGs respectively

Lifetime health advisories (LTHAs) are calculated from the drinking water equivalent level (DWEL) and represent the concentration of a substance in drinking water estimated to have negligible deleterious effects in humans over a lifetime of 70 years assuming 2 liter per day water consumption for a 70-kilogram adult In the absence of chemical-specific data LTHAs are 20 and 10 of the corresponding DWELs for noncarcinogenic organic and inorganic compounds respectively LTHAs are not derived for compounds that are potentially carcinogenic for humans

Maximum contaminant levels (MCLs) are drinking water standards established by the EPA They represent levels of substances in drinking water that EPA deems protective of public health over a lifetime (70 years) at an adult exposure rate of 2 liters of water per day They differ from other protective comparison values in that they (1) reflect consideration of both carcinogenic and noncarcinogenic effects (2) take into account the availability and economics of water treatment technology and (3) are legally enforceable

Maximum contaminant level action (MCLA) are action levels for drinking water set by EPA under Superfund When the relevant action level is exceeded a regulatory response is triggered

When screening individual chemical substances ATSDR staff compares the highest single concentration of a chemical detected at the site with the appropriate CV available for the most sensitive of the potentially exposed individuals (usually children) Typically the cancer risk evaluation guide (CREG) or chronic environmental media evaluation guide (cEMEG) is used This worst-case approach introduces a high degree of conservatism into the analysis and often results in the selection of many chemical substances for further public health evaluation that upon closer scrutiny will not be judged to pose any hazard to human health In the interest of public health it is however more prudent to use an environmental screen that identifies many chemicals for further evaluation that may later be determined to be harmless as opposed to one that may overlook even a single potential hazard to public health The reader should keep in mind the conservativeness of this approach when interpreting ATSDRrsquos analysis of the potential health implications of site-specific exposures

A-3

Appendix B Tables

B-1

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n IN

OR

GA

NIC

MO

ITIE

S N

itrat

es

100

-- 2

335

0 8

164

860

0 P

oten

tial P

ublic

Hea

lth C

once

rn

Sul

fate

s 6

000

600

0 6

000

No

App

aren

t Pub

lic H

ealth

Haz

ard

MET

ALS

A

lum

inum

20

0 --

17

00

950

950

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bar

ium

16

-- 4

00

164

90

No

App

aren

t Pub

lic H

ealth

Haz

ard

Cal

cium

21

000

-- 9

500

0 58

000

58

000

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 1

2 --

26

2

1 2

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r 14

-- 6

0 37

6

38

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron

14 --

55

00

173

6 19

5 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Le

ad

2 --

28

89

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mag

nesi

um

160

0 --

12

000

698

3 7

250

No

App

aren

t Pub

lic H

ealth

Haz

ard

Man

gane

se

42

-- 8

30

153

1 78

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ercu

ry

1 --

7

28

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Nic

kel

23

-- 4

2

325

3

25

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um

130

0 --

70

00

299

0 2

150

No

App

aren

t Pub

lic H

ealth

Haz

ard

Sod

ium

5

300

-- 1

500

0 10

150

10

150

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Zi

nc

28 --

25

00

541

155

No

App

aren

t Pub

lic H

ealth

Haz

ard

OR

GA

NIC

CO

MPO

UN

DS

Ace

tone

5

-- 2

33

719

47

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ben

zene

0

4 0

4 0

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

rom

odic

hlor

omet

hane

3

3 3

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

04

04

04

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

0

6 --

39

134

6 0

78

No

App

aren

t Pub

lic H

ealth

Haz

ard

Dib

rom

ochl

orom

etha

ne

1 1

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

03

-- 4

8 24

24

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

4-D

ichl

orob

enze

ne

027

-- 4

4 3

91

077

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

1-D

ichl

oroe

than

e 0

4 --

15

0

7 0

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

oroe

than

e 0

53

053

0

53

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

043

-- 3

5

13

08

No

App

aren

t Pub

lic H

ealth

Haz

ard

Met

hyle

ne C

hlor

ide

2 2

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d

B-2

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

Reference dose media evaluation guide (RMEG) is the concentration of a contaminant in air water or soil that ATSDR derives from EPArsquos RfD for that contaminant by factoring in default values for body weight and the media-specific intake rate Like ATSDR EMEGs RMEGs are calculated for both adults and children

Risk-based concentrations (RBCs) are media-specific values derived by the Region III Office of the US Environmental Protection Agency from EPA RfDs RfCs or cancer slope factors by factoring in default values for body weight exposure duration and ingestioninhalation rates These values represent levels of chemicals in air water soil and fish that are considered safe over a lifetime of exposure RBCs for noncarcinogens and carcinogens are analogous to ATSDR EMEGs and CREGs respectively

Lifetime health advisories (LTHAs) are calculated from the drinking water equivalent level (DWEL) and represent the concentration of a substance in drinking water estimated to have negligible deleterious effects in humans over a lifetime of 70 years assuming 2 liter per day water consumption for a 70-kilogram adult In the absence of chemical-specific data LTHAs are 20 and 10 of the corresponding DWELs for noncarcinogenic organic and inorganic compounds respectively LTHAs are not derived for compounds that are potentially carcinogenic for humans

Maximum contaminant levels (MCLs) are drinking water standards established by the EPA They represent levels of substances in drinking water that EPA deems protective of public health over a lifetime (70 years) at an adult exposure rate of 2 liters of water per day They differ from other protective comparison values in that they (1) reflect consideration of both carcinogenic and noncarcinogenic effects (2) take into account the availability and economics of water treatment technology and (3) are legally enforceable

Maximum contaminant level action (MCLA) are action levels for drinking water set by EPA under Superfund When the relevant action level is exceeded a regulatory response is triggered

When screening individual chemical substances ATSDR staff compares the highest single concentration of a chemical detected at the site with the appropriate CV available for the most sensitive of the potentially exposed individuals (usually children) Typically the cancer risk evaluation guide (CREG) or chronic environmental media evaluation guide (cEMEG) is used This worst-case approach introduces a high degree of conservatism into the analysis and often results in the selection of many chemical substances for further public health evaluation that upon closer scrutiny will not be judged to pose any hazard to human health In the interest of public health it is however more prudent to use an environmental screen that identifies many chemicals for further evaluation that may later be determined to be harmless as opposed to one that may overlook even a single potential hazard to public health The reader should keep in mind the conservativeness of this approach when interpreting ATSDRrsquos analysis of the potential health implications of site-specific exposures

A-3

Appendix B Tables

B-1

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n IN

OR

GA

NIC

MO

ITIE

S N

itrat

es

100

-- 2

335

0 8

164

860

0 P

oten

tial P

ublic

Hea

lth C

once

rn

Sul

fate

s 6

000

600

0 6

000

No

App

aren

t Pub

lic H

ealth

Haz

ard

MET

ALS

A

lum

inum

20

0 --

17

00

950

950

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bar

ium

16

-- 4

00

164

90

No

App

aren

t Pub

lic H

ealth

Haz

ard

Cal

cium

21

000

-- 9

500

0 58

000

58

000

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 1

2 --

26

2

1 2

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r 14

-- 6

0 37

6

38

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron

14 --

55

00

173

6 19

5 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Le

ad

2 --

28

89

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mag

nesi

um

160

0 --

12

000

698

3 7

250

No

App

aren

t Pub

lic H

ealth

Haz

ard

Man

gane

se

42

-- 8

30

153

1 78

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ercu

ry

1 --

7

28

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Nic

kel

23

-- 4

2

325

3

25

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um

130

0 --

70

00

299

0 2

150

No

App

aren

t Pub

lic H

ealth

Haz

ard

Sod

ium

5

300

-- 1

500

0 10

150

10

150

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Zi

nc

28 --

25

00

541

155

No

App

aren

t Pub

lic H

ealth

Haz

ard

OR

GA

NIC

CO

MPO

UN

DS

Ace

tone

5

-- 2

33

719

47

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ben

zene

0

4 0

4 0

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

rom

odic

hlor

omet

hane

3

3 3

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

04

04

04

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

0

6 --

39

134

6 0

78

No

App

aren

t Pub

lic H

ealth

Haz

ard

Dib

rom

ochl

orom

etha

ne

1 1

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

03

-- 4

8 24

24

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

4-D

ichl

orob

enze

ne

027

-- 4

4 3

91

077

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

1-D

ichl

oroe

than

e 0

4 --

15

0

7 0

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

oroe

than

e 0

53

053

0

53

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

043

-- 3

5

13

08

No

App

aren

t Pub

lic H

ealth

Haz

ard

Met

hyle

ne C

hlor

ide

2 2

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d

B-2

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

Appendix B Tables

B-1

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n IN

OR

GA

NIC

MO

ITIE

S N

itrat

es

100

-- 2

335

0 8

164

860

0 P

oten

tial P

ublic

Hea

lth C

once

rn

Sul

fate

s 6

000

600

0 6

000

No

App

aren

t Pub

lic H

ealth

Haz

ard

MET

ALS

A

lum

inum

20

0 --

17

00

950

950

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bar

ium

16

-- 4

00

164

90

No

App

aren

t Pub

lic H

ealth

Haz

ard

Cal

cium

21

000

-- 9

500

0 58

000

58

000

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 1

2 --

26

2

1 2

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r 14

-- 6

0 37

6

38

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron

14 --

55

00

173

6 19

5 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Le

ad

2 --

28

89

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mag

nesi

um

160

0 --

12

000

698

3 7

250

No

App

aren

t Pub

lic H

ealth

Haz

ard

Man

gane

se

42

-- 8

30

153

1 78

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ercu

ry

1 --

7

28

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Nic

kel

23

-- 4

2

325

3

25

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um

130

0 --

70

00

299

0 2

150

No

App

aren

t Pub

lic H

ealth

Haz

ard

Sod

ium

5

300

-- 1

500

0 10

150

10

150

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Zi

nc

28 --

25

00

541

155

No

App

aren

t Pub

lic H

ealth

Haz

ard

OR

GA

NIC

CO

MPO

UN

DS

Ace

tone

5

-- 2

33

719

47

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ben

zene

0

4 0

4 0

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

rom

odic

hlor

omet

hane

3

3 3

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

04

04

04

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

0

6 --

39

134

6 0

78

No

App

aren

t Pub

lic H

ealth

Haz

ard

Dib

rom

ochl

orom

etha

ne

1 1

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

03

-- 4

8 24

24

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

4-D

ichl

orob

enze

ne

027

-- 4

4 3

91

077

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

1-D

ichl

oroe

than

e 0

4 --

15

0

7 0

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

oroe

than

e 0

53

053

0

53

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

043

-- 3

5

13

08

No

App

aren

t Pub

lic H

ealth

Haz

ard

Met

hyle

ne C

hlor

ide

2 2

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d

B-2

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n IN

OR

GA

NIC

MO

ITIE

S N

itrat

es

100

-- 2

335

0 8

164

860

0 P

oten

tial P

ublic

Hea

lth C

once

rn

Sul

fate

s 6

000

600

0 6

000

No

App

aren

t Pub

lic H

ealth

Haz

ard

MET

ALS

A

lum

inum

20

0 --

17

00

950

950

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bar

ium

16

-- 4

00

164

90

No

App

aren

t Pub

lic H

ealth

Haz

ard

Cal

cium

21

000

-- 9

500

0 58

000

58

000

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 1

2 --

26

2

1 2

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r 14

-- 6

0 37

6

38

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron

14 --

55

00

173

6 19

5 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Le

ad

2 --

28

89

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mag

nesi

um

160

0 --

12

000

698

3 7

250

No

App

aren

t Pub

lic H

ealth

Haz

ard

Man

gane

se

42

-- 8

30

153

1 78

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ercu

ry

1 --

7

28

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Nic

kel

23

-- 4

2

325

3

25

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um

130

0 --

70

00

299

0 2

150

No

App

aren

t Pub

lic H

ealth

Haz

ard

Sod

ium

5

300

-- 1

500

0 10

150

10

150

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Zi

nc

28 --

25

00

541

155

No

App

aren

t Pub

lic H

ealth

Haz

ard

OR

GA

NIC

CO

MPO

UN

DS

Ace

tone

5

-- 2

33

719

47

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ben

zene

0

4 0

4 0

4 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

rom

odic

hlor

omet

hane

3

3 3

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

04

04

04

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

0

6 --

39

134

6 0

78

No

App

aren

t Pub

lic H

ealth

Haz

ard

Dib

rom

ochl

orom

etha

ne

1 1

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

03

-- 4

8 24

24

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

4-D

ichl

orob

enze

ne

027

-- 4

4 3

91

077

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

1-D

ichl

oroe

than

e 0

4 --

15

0

7 0

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

oroe

than

e 0

53

053

0

53

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

043

-- 3

5

13

08

No

App

aren

t Pub

lic H

ealth

Haz

ard

Met

hyle

ne C

hlor

ide

2 2

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d

B-2

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

2 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Faci

lity

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

1991

-- 1

999)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Mar

ch 2

002

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n Te

trach

loro

ethe

ne (P

CE

) 0

29 --

05

3 0

41

041

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Tr

ichl

oroe

then

e (T

CE

) 0

27 --

08

9 0

5 0

35

No

App

aren

t Pub

lic H

ealth

Haz

ard

Xyl

enes

0

5 --

51

2

2 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Reference

Agency for Toxic Substances and Disease Registry March 29 2002 Health

Consultation Sigmonrsquos Septic Tank Service Facility (Review of Groundwater

Data) US DHHS Public Health Service Atlanta GA

B-3

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n M

ETA

LS

Alu

min

um

56 --

200

10

72

110

No

App

aren

t Pub

lic H

ealth

Haz

ard

Ars

enic

1

2 --

12

1

2 1

2 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

ariu

m

12 --

130

34

31

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d B

eryl

lium

0

14 --

01

4 0

14

014

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

alci

um5

170

0 --

39

000

798

94

590

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

obal

t 0

08 --

36

0

27

027

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

oppe

r2 2

8 --

270

45

21

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

Iron1

37 --

250

83

78

79

No

App

aren

t Pub

lic H

ealth

Haz

ard

Lead

2 1

3 --

140

6

04

5 P

oten

tial P

ublic

Hea

lth C

once

rn

Mag

nesi

um5

390

-- 6

900

1

217

31

135

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

anga

nese

1 5

3

6 --

270

11

87

82

No

App

aren

t Pub

lic H

ealth

Haz

ard

Mer

cury

5 0

98 --

21

1

43

154

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d N

icke

l 1

3 --

32

2

19

24

No

App

aren

t Pub

lic H

ealth

Haz

ard

Pot

assi

um5

840

-- 3

100

1

447

75

130

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

elen

ium

0

43 --

04

3 0

43

043

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

ilver

0

07 --

00

7 0

07

007

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

odiu

m3

910

-- 9

400

3

958

84

410

0 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d S

tront

ium

12

-- 1

80

261

2 25

5

No

App

aren

t Pub

lic H

ealth

Haz

ard

Van

adiu

m

045

-- 1

8

09

113

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Y

ttriu

m

21

-- 2

1

21

21

No

App

aren

t Pub

lic H

ealth

Haz

ard

Zinc

1 4

9 --

34

00

548

2 42

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

026

-- 0

26

026

0

26

No

App

aren

t Pub

lic H

ealth

Haz

ard

Bro

mof

orm

4 1

6 --

16

1

6 1

6 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d C

arbo

n D

isul

fide

16

-- 1

6

16

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orob

enze

ne

054

-- 0

54

054

0

54

No

App

aren

t Pub

lic H

ealth

Haz

ard

Chl

orof

orm

4 0

32 --

03

2 0

32

032

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 1

2-D

ichl

orob

enze

ne

017

-- 0

46

028

0

32

No

App

aren

t Pub

lic H

ealth

Haz

ard

B-4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 2

C

hem

ical

Lev

els

Con

side

red

a N

o A

ppar

ent H

ealth

Haz

ard

A

TSD

Rs

200

6 Pu

blic

Hea

lth R

espo

nse

for S

igm

ons

Sep

tic T

ank

Serv

ice

Site

(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls b

etw

een

Oct

ober

200

2 --

May

200

4)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

ATS

DR

PU

BLI

C H

EALT

H C

ON

CLU

SIO

N

AS

CIT

ED IN

Sep

tem

ber 2

005

HEA

LTH

CO

NSU

LTA

TIO

N

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n 1

4-D

ichl

orob

enze

ne

1 --

22

1

48

16

No

App

aren

t Pub

lic H

ealth

Haz

ard

11-

Dic

hlor

oeth

ane

02

-- 0

69

037

0

45

No

App

aren

t Pub

lic H

ealth

Haz

ard

cis-

12-

Dic

hlor

oeth

ene

052

-- 0

52

052

0

52

No

App

aren

t Pub

lic H

ealth

Haz

ard

12-

Dic

hlor

opro

pane

0

67 --

06

7 0

67

067

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d 2-

Hex

anon

e 0

52 --

05

2 0

52

052

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l Ace

tate

0

91 --

09

1 0

91

091

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

lcyc

lohe

xane

0

12 --

01

2 0

12

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d M

ethy

l-T-B

utyl

Eth

er (M

TBE

) 0

26 --

03

9 0

32

033

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d Te

trach

loro

ethe

ne (P

CE

) 0

1 --

02

1 0

14

012

N

o A

ppar

ent P

ublic

Hea

lth H

azar

d PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

002

7 --

00

27

002

7 0

027

No

App

aren

t Pub

lic H

ealth

Haz

ard

End

osul

fan

II 0

011

-- 0

011

0

011

001

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ald

ehyd

e 0

017

-- 0

017

0

017

001

7 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d E

ndrin

Ket

one

001

-- 0

01

001

0

01

No

App

aren

t Pub

lic H

ealth

Haz

ard

Gam

ma-

Chl

orda

ne

001

1 --

06

7 0

086

034

1 N

o A

ppar

ent P

ublic

Hea

lth H

azar

d H

epta

chlo

r Epo

xide

0

01 --

00

32

002

0

02

No

App

aren

t Pub

lic H

ealth

Haz

ard

Reference

Agency for Toxic Substances and Disease Registry February 2006 Health

Consultation Sigmonrsquos Septic Tank Service Site (Review of Groundwater Data shy

EPA Delineation Investigations of 2002 2003 and 2004) US DHHS Public Health

Service Atlanta GA

B-5

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE N

OTE

S

Foot

note

s fo

r Tab

les

3 th

roug

h 11

No

te

s

A substance is selected for further public health evaluation if its maximum detected level in groundwater exceeds its respective water comparison

value (see blue highlighting)

This screening criteria is neglected if the No 5 disclaimer is specified (see lavender highlighting) Moreover a

substance may also be selected for further public health evaluation if detected and no available water comparison value exists for the substance

(see yellow highlighting) however this screening criteria is also neglected if the No 5 disclaimer is specified (see green highlighting)

Therefore a response of Yes under the column labeled Further Public Health Evaluation Required indicated that the substance was further

evaluated by ATSDR health scientists

CR

EG

Cancer Risk Evaluation Guide

EM

EG

Environmental Media Evaluation Guide (prefixes a = acute c = chronic and i = intermediate)

LT

HA

Drinking Water Lifetime Health Advisory

MC

L Maximum Contaminant Level

RB

C

Risk Based Concentration

(Note RBC values derived from equations documented in following reference

EPA Region III Risk-Based

Concentration Table United States Environmental Protection Agency Region III 841 Chestnut Street Philadelphia PA 19107

Available on EPA

Region IIIrsquos Internet website httpwwwepagovreg3hwmdriskriskmenuhtm Background Information - [PDF])

RM

EG

Reference Dose Media Evaluation Guide

pp

b parts per billion

1Listed value in EPA MCL column is a Secondary Drinking Water Regulation (SDWR) as set by EPA

SDWRs are unenforceable federal guidelines

regarding taste odor color and other non-aesthetic effects of drinking water

EPA recommends them to States as reasonable goals but federal law

does not require water supply systems to comply with them

States may however adopt their own enforceable regulations governing these concerns

To be safe check your States drinking water regulations

2Listed value in EPA MCL column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund If the relevant

action level is exceeded a regulatory response is triggered

3Listed value in EPA MCL column is a health-based Drinking Water Advisory as set by EPA

The Drinking Water Advisory is based on the assumption

that an individual is placed on a sodium restricted diet of 500 mgday

4Listed value in EPA MCL column is a proposed MCL under the 1994 proposed rule for disinfection by products rule the current MCL for most

trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report

5Detected concentration(s)are within a range of concentration levels designated for the specific chemical and considered a no apparent public health

hazard as cited in a previous public health consultation released for the Sigmon Septic Tank Service site (ATSDR 2002)

B-6

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 3

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

1

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

34

700

child

RM

EG

2

000

No

Cal

cium

5 2

700

J N

o C

obal

t 0

11 J

10

0 ch

ild iE

ME

G

No

Cop

per2

28 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

37

J 15

N

o M

agne

sium

5 50

0 J

No

Man

gane

se1

82

300

LTH

A

50

No

Pot

assi

um5

160

0 J

No

Zinc

1 35

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

120

0 20

000

chi

ld R

ME

G

100

00

No

B-7

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

041

J

002

CR

EG

10

N

o B

ariu

m

72

700

child

RM

EG

2

000

No

Cal

cium

5 48

000

N

o C

obal

t 0

79 J

10

0 ch

ild iE

ME

G

No

Cop

per2

14

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

J

110

00 R

BC

30

0 N

o M

agne

sium

5 4

300

J N

o M

anga

nese

15

71

300

LTH

A

50

No

Mer

cury

5 0

2 2

LTH

A

2 N

o N

icke

l 1

5 10

0 LT

HA

N

o P

otas

sium

5 3

600

J N

o S

ilver

0

03 J

50

chi

ld R

ME

G

No

Sod

ium

3 6

600

200

00

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Van

adiu

m

19

30 c

hild

iEM

EG

N

o Zi

nc1

28

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

enze

ne

054

0

6 C

RE

G

5 N

o C

hlor

oben

zene

2

2 10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

600

LTH

A

600

No

14-

Dic

hlor

oben

zene

2

5 75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 J

0

03 C

RE

G

2 Y

es

Tota

l Xyl

enes

0

39 J

2

000

child

iEM

EG

10

000

N

o

B-8

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 4

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

3

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

130

00

200

00 c

hild

RM

EG

10

000

Y

es

B-9

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 5

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

4

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

100

700

child

RM

EG

2

000

No

Ber

ylliu

m

012

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

610

0 N

o C

obal

t 0

41 J

10

0 ch

ild iE

ME

G

No

Cop

per2

23 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

16

J 15

N

o M

agne

sium

5 2

400

J N

o M

anga

nese

1 19

30

0 LT

HA

50

N

o N

icke

l 1

8 10

0 LT

HA

N

o P

otas

sium

5 3

200

J N

o S

odiu

m3

430

0 J

200

00

No

Thal

lium

0

09 J

0

5 LT

HA

2

No

Zinc

1 13

0 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

630

0 20

000

chi

ld R

ME

G

100

00

No

B-1

0

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 6

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

5

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

50

700

child

RM

EG

2

000

No

Cal

cium

5 5

200

No

Cob

alt

035

J

100

child

iEM

EG

N

o C

oppe

r2 33

J

200

child

iEM

EG

1

300

No

Lead

2 1

1 J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

49

300

LTH

A

50

No

Nic

kel

23

100

LTH

A

No

Pot

assi

um5

200

0 J

No

Thal

lium

0

06 J

0

5 LT

HA

2

No

Zinc

1 18

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

PEST

ICID

ES

Hep

tach

lor E

poxi

de

000

95 J

0

004

CR

EG

0

2 N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

1

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 7

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

27 J

10

0 ch

ild iE

ME

G

No

Cop

per2

16 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

11

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

14

300

LTH

A

50

No

Nic

kel

19

100

LTH

A

No

Pot

assi

um5

140

0 J

No

Thal

lium

0

07 J

0

5 LT

HA

2

No

Zinc

1 17

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

200

00 c

hild

RM

EG

10

000

N

o

B-1

2

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 8

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

6 (D

uplic

ate

Sam

ple)

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

30

700

child

RM

EG

2

000

No

Cal

cium

5 3

200

J N

o C

obal

t 0

28 J

10

0 ch

ild iE

ME

G

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

13

J 15

N

o M

agne

sium

5 71

0 J

No

Man

gane

se1

13

300

LTH

A

50

No

Nic

kel

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Th

alliu

m

007

J

05

LTH

A

2 N

o Zi

nc1

20 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

16

0 20

000

chi

ld R

ME

G

100

00

No

B-1

3

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 9

D

etec

ted

Subs

tanc

es fo

und

in P

rivat

e W

ell P

W-0

7

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

17

700

child

RM

EG

2

000

No

Cal

cium

5 2

300

J N

o C

oppe

r2 9

8 J

200

child

iEM

EG

1

300

No

Mag

nesi

um5

590

J N

o N

icke

l 0

19 J

10

0 LT

HA

N

o P

otas

sium

5 1

500

J N

o S

odiu

m3

510

0 20

000

N

o V

anad

ium

1

2 30

chi

ld iE

ME

G

No

Zinc

1 19

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

640

200

00 c

hild

RM

EG

10

000

N

o

B-1

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

0

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-08

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

13

700

child

RM

EG

2

000

No

Cal

cium

5 8

200

No

Cop

per2

45

J 20

0 ch

ild iE

ME

G

130

0 N

o M

agne

sium

5 1

700

J N

o M

anga

nese

1 1

3 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 2

100

J N

o S

odiu

m3

560

0 20

000

N

o V

anad

ium

2

1 30

chi

ld iE

ME

G

No

Zinc

1 69

J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

SEM

I-VO

LATI

LE O

RG

AN

IC C

OM

POU

ND

S B

is(2

-eth

yhex

yl)p

htha

lat e

6

2 3

CR

EG

6

Yes

C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

2

000

200

00 c

hild

RM

EG

10

000

N

o

B-1

5

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

1

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-09

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

16

700

child

RM

EG

2

000

No

Ber

ylliu

m

008

J

20 c

hild

cE

ME

G

4 N

o C

alci

um5

960

0 N

o C

obal

t 0

04 J

10

0 ch

ild iE

ME

G

No

Cop

per2

17 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

43

J 15

N

o M

agne

sium

5 1

200

J N

o M

anga

nese

1 2

7 30

0 LT

HA

50

N

o N

icke

l 0

35 J

10

0 LT

HA

N

o P

otas

sium

5 1

400

J N

o Zi

nc1

22 J

3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

T S

Nitr

ates

68

0 20

000

chi

ld R

ME

G

100

00

No

B-1

6

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

2

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-10

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

11

700

child

RM

EG

2

000

No

Cal

cium

5 4

600

J N

o C

obal

t 0

19 J

10

0 ch

ild iE

ME

G

No

Cop

per2

32

J 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 49

0 11

000

RB

C

300

No

Lead

2 11

J

15

No

Mag

nesi

um5

110

0 J

No

Man

gane

se1

18

300

LTH

A

50

No

Nic

kel

035

J

100

LTH

A

No

Pot

assi

um5

170

0 J

No

Sod

ium

3 11

000

20

000

N

o V

anad

ium

1

3 30

chi

ld iE

ME

G

No

Zinc

1 2

600

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o C

LASS

ICA

L N

UTR

IEN

TS

Nitr

ates

1

300

200

00 c

hild

RM

EG

10

000

N

o

B-1

7

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

3

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-11

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

A

rsen

ic

029

J

002

CR

EG

10

N

o B

ariu

m

45

J 70

0 ch

ild R

ME

G

200

0 N

o C

alci

um5

100

00

No

Cop

per2

20 J

20

0 ch

ild iE

ME

G

130

0 N

o Le

ad2

27

J 15

N

o M

agne

sium

5 1

500

J N

o M

anga

nese

1 3

6 30

0 LT

HA

50

N

o N

icke

l 0

34 J

10

0 LT

HA

N

o P

otas

sium

5 2

000

J N

o S

odiu

m3

840

0 20

000

N

o V

anad

ium

3

2 30

chi

ld iE

ME

G

No

Zinc

1 1

500

J 3

000

child

iEM

EG

5

000

(SD

WR

) N

o PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 J

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

J 0

02 C

RE

G

No

Gam

ma-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Gam

ma

orLi

ndan

e)

000

27 J

0

1 ch

ild iE

ME

G

02

No

CLA

SSIC

AL

NU

TRIE

NT S

N

itrat

es

150

0 20

000

chi

ld R

ME

G

100

00

No

B-1

8

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

4

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

l PW

-12

C

HEM

ICA

L SU

BST

AN

CE

CH

EMIC

AL

CO

NC

ENTR

ATI

ON

S (p

pb)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

A

pril

18 2

005

MET

ALS

B

ariu

m

29

700

child

RM

EG

2

000

No

Cal

cium

5 3

100

J N

o C

obal

t 0

16 J

10

0 ch

ild iE

ME

G

No

Cop

per2

37 J

20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 66

J

110

00 R

BC

30

0 N

o Le

ad2

24

J 15

N

o M

agne

sium

5 59

0 J

No

Man

gane

se1

25

300

LTH

A

50

No

Nic

kel

056

J

100

LTH

A

No

Pot

assi

um5

160

0 J

No

Thal

lium

0

05 J

0

5 LT

HA

2

No

Zinc

1 8

9 J

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

390

200

00 c

hild

RM

EG

10

000

N

o

B-1

9

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

TAB

LE 1

5

Det

ecte

d Su

bsta

nces

foun

d in

Priv

ate

Wel

ls n

ear t

he S

igm

on F

acili

ty(S

umm

ary

of D

etec

ted

Che

mic

al C

once

ntra

tions

foun

d in

all

Priv

ate

Wel

ls o

n A

pril

2005

)

CH

EMIC

AL

SUB

STA

NC

E C

HEM

ICA

L C

ON

CEN

TRA

TIO

NS

(ppb

)

WA

TER

C

OM

PAR

ISO

N V

ALU

ES

(ppb

)

EPA

M

CL

(ppb

)

FUR

THER

PU

BLI

C

HEA

LTH

EV

ALU

ATI

ON

R

EQU

IRED

Det

ecte

d C

once

ntra

tions

Ran

ge

Mea

n M

edia

n D

etec

tion

Rat

e M

ETA

LS

Ars

enic

0

29 --

04

1 0

34

035

2

12

002

CR

EG

10

N

o B

ariu

m

45

-- 1

00

248

7 29

50

121

2 70

0 ch

ild R

ME

G

200

0 N

o B

eryl

lium

0

08 --

01

2 0

10

010

2

12

20 c

hild

cE

ME

G

4 N

o C

alci

um5

230

0 --

48

000

885

000

5

662

58

121

2 N

o C

obal

t 0

04 --

07

9 0

22

027

9

12

100

child

iEM

EG

N

o C

oppe

r2 1

4 --

37

126

6 18

50

121

2 20

0 ch

ild iE

ME

G

130

0 N

o Iro

n1 63

-- 4

90

126

77

660

0 3

12

110

00 R

BC

30

0 N

o Le

ad2

11

-- 1

1 2

42

240

9

12

15

No

Mag

nesi

um5

500

-- 4

300

1

106

07

110

000

12

12

No

Man

gane

se1

5

13

-- 7

1 9

49

130

0 11

12

300

LTH

A

50

No

Mer

cury

5 0

2 --

02

0

20

020

1

12

2 LT

HA

2

No

Nic

kel

019

-- 2

3

074

0

56

111

2 10

0 LT

HA

N

o P

otas

sium

5 1

400

-- 3

600

1

861

69

165

000

12

12

No

Silv

er

003

-- 0

03

003

0

03

112

50

chi

ld R

ME

G

No

Sod

ium

3 4

300

-- 1

100

0 6

492

43

610

000

6

12

200

00

No

Thal

lium

0

05 --

00

9 0

07

007

6

12

05

LTH

A

2 N

o V

anad

ium

1

2 --

32

1

82

190

5

12

30 c

hild

iEM

EG

N

o Zi

nc1

28

-- 2

600

45

47

210

0 12

12

300

0 ch

ild iE

ME

G

500

0 (S

DW

R)

No

VOLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Ben

zene

0

54 --

05

4 0

54

054

1

12

06

CR

EG

5

No

Chl

orob

enze

ne

22

-- 2

2

220

2

20

112

10

0 LT

HA

10

0 N

o 1

2-D

ichl

orob

enze

ne

14

-- 1

4

140

1

40

112

60

0 LT

HA

60

0 N

o 1

4-D

ichl

orob

enze

ne

25

-- 2

5

250

2

50

112

75

LTH

A

75

No

11-

Dic

hlor

oeth

ane

084

-- 0

84

084

0

84

112

80

0 R

BC

N

o ci

s-1

2-D

ichl

oroe

then

e 0

83 --

08

3 0

83

083

1

12

70 L

THA

70

N

o 1

12-

Tric

hlor

o-1

22-

Trifl

uoro

etha

ne (F

reon

113

) 0

55 --

05

5 0

55

055

1

12

300

000

child

RM

EG

N

o V

inyl

Chl

orid

e 0

21 --

02

1 0

21

021

1

12

003

CR

EG

2

Yes

To

tal X

ylen

es

039

-- 0

39

039

0

39

112

2

000

child

iEM

EG

10

000

N

o SE

MI-V

OLA

TILE

OR

GA

NIC

CO

MPO

UN

DS

Bis

(2-e

thyh

exyl

)pht

hala

te

62

-- 6

2

62

62

112

3

CR

EG

6

Yes

PE

STIC

IDES

al

pha-

BH

C (H

exac

hlor

ocyc

lohe

xane

-Alp

ha)

000

42 --

00

042

000

42

000

42

112

0

006

CR

EG

N

o be

ta-B

HC

(Hex

achl

oroc

yclo

hexa

ne-B

eta)

0

004

-- 0

004

0

004

000

4 1

12

002

CR

EG

N

o ga

mm

a-B

HC

(Hex

achl

oroc

yclo

hexa

ne-G

amm

a or

Lind

ane)

0

0027

-- 0

002

7 0

0027

0

0027

1

12

01

child

iEM

EG

0

2 N

o H

epta

chlo

r Epo

xide

0

0095

-- 0

009

5 0

0095

0

0095

1

12

000

4 C

RE

G

02

No

CLA

SSIC

AL

NU

TRIE

NTS

N

itrat

es

150

-- 1

300

0 1

060

77

125

000

12

12

200

00 c

hild

RM

EG

10

000

Y

es

B-2

0

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

Appendix C Figures

C-1

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

STORAGE SHED

WASTE PILE

OPEN PITS

RESIDENCE

RESIDEN

REP - USGS 75 MINUTE SERIES TOPOGRAPHIC MAP TROUTMAN NC 1993 1 = 600

SITE LAYOUT MAP SIGMON S SEPTIC TANK SITE FIGURE

STATESVILLE IREDELL COUNTY NORTH CAROLINA 1

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

S i g

mo

n P

on

dS

i gm

on

Po

nd

Mu

s t a

ng

La

ne

Mu

st a

ng

La

ne

Lo

w L

an

eL

ow

La

ne

S h o t g u n L a n eS h o t g u n L a n e

u f o l a R o a du f o l a R o a d

La

mb

er

th P

on

dL

am

be

rth

Po

nd

W il

li a

m s

Po

n d

Wil

lia

ms

Po

n d

D a

v i d

s o

n P

o n

dD

a v

i ds

on

Po

nd

L a u r e n D r i v eL a u r e n D r i v e

SS

-MW

-10

B

SS

-MW

-11

C

SS

-MW

-01

SS

-MW

-14

SS

-MW

-12

B

SS-PP-08

-PP-07

SS

-MW

-13

B

SS

-PW

-04

SS

-PW

-03

SS

-PW

-01

SS

-PW

-10

SS

-PW

-09

SS

-PW

-08

SS

-PW

-06

SS

-PW

-05

2004 ACTUAL RI GROUNDWATER PUSHPOINT amp POTABLE WATER LOCATION MAP

SIGMONS SEPTIC TANK SITE STATESVILLE IREDELL COUNTY NORTH CAROLINA

Leg

end M

onito

ring

Wel

l

Pot

able

Wel

l

1 in

equ

als

400

ftS

CA

LE

Fig

ure

3

4

4